Bump minimum supported python to 3.12

[msimberg]

As a follow-up to #1197 which adds support for python 3.14, this bumps the minimum version to 3.12 and applies some modernizations along the way.

[msimberg]

cscs-ci run default

[github-actions]

Mandatory Tests

Please make sure you run these tests via comment before you merge!

• cscs-ci run default
• cscs-ci run distributed

Optional Tests

To run benchmarks you can use:

• cscs-ci run benchmark-bencher

To run tests and benchmarks with the DaCe backend you can use:

• cscs-ci run dace

To run test levels ignored by the default test suite (mostly simple datatest for static fields computations) you can use:

• cscs-ci run extra

For more detailed information please look at CI in the EXCLAIM universe.

[msimberg]

cscs-ci run default

[Copilot]

Pull request overview

This PR raises the project’s minimum supported Python version to 3.12 and modernizes the codebase to take advantage of Python 3.12+ typing and stdlib features, while updating CI/test configuration to match.

Changes:

• Bump requires-python across workspace packages to >=3.12, update .python-version, and adjust GitHub Actions matrices accordingly.
• Modernize typing/code style (PEP 695 generics, type aliases, enum.StrEnum, stdlib Buffer/Required) and align Ruff’s target version to py312.
• Minor formatting/cleanup adjustments in scripts and CI YAML.

Reviewed changes

Copilot reviewed 53 out of 54 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tools/src/icon4py/tools/py2fgen/runtime_config.py	Switch to PEP 695 generic syntax for enum env parsing helper.
tools/src/icon4py/tools/py2fgen/_export.py	Handle TypeAliasType and migrate TypeAlias declarations to type statements.
tools/src/icon4py/tools/py2fgen/_definitions.py	Update type alias style (type statements) and add UP040 suppressions where needed.
tools/src/icon4py/tools/py2fgen/_conversion.py	Remove a previous overload type-ignore around np.frombuffer(...).reshape(...).
tools/pyproject.toml	Bump minimum Python to 3.12 and update classifiers.
scripts/python/test_conventions.py	Convert TypeAlias to type statement for fixture location.
scripts/python/helpers/pyproject.py	Minor formatting cleanup.
scripts/python/compare_icon4py_openacc.py	Convert TypeAlias to type statement for variant descriptor.
pyproject.toml	Bump minimum Python to 3.12 and set Ruff target-version = py312.
noxfile.py	Update parameter-set typing to type aliases and adjust how args are extracted; drop 3.10/3.11 from supported versions list.
model/testing/src/icon4py/model/testing/test_utils.py	Use stdlib Buffer and remove a type ignore in fingerprint_buffer.
model/testing/src/icon4py/model/testing/serialbox.py	Convert TypeAlias to type statements for Literal index aliases.
model/testing/src/icon4py/model/testing/filters.py	Convert predicate alias to PEP 695 generic type.
model/testing/pyproject.toml	Bump minimum Python to 3.12 and drop typing-extensions dependency.
model/standalone_driver/tests/standalone_driver/integration_tests/test_standalone_driver.py	Use datetime.UTC for tzinfo.
model/standalone_driver/src/icon4py/model/standalone_driver/config.py	Add UP040 suppressions to keep TypeAlias where desired.
model/standalone_driver/pyproject.toml	Bump minimum Python to 3.12.
model/driver/src/icon4py/model/driver/initialization_utils.py	Switch enums to enum.StrEnum.
model/driver/pyproject.toml	Bump minimum Python to 3.12.
model/common/tests/common/grid/unit_tests/test_simple.py	Adjust exception handling line (removes a PERF203 suppression).
model/common/src/icon4py/model/common/utils/fortran_config.py	Convert TypeVar-based generics to PEP 695 generic functions.
model/common/src/icon4py/model/common/utils/device_utils.py	Convert synchronized_function typing to PEP 695 generics.
model/common/src/icon4py/model/common/utils/data_allocation.py	Convert some aliases to type statements and use PEP 695 generic function syntax.
model/common/src/icon4py/model/common/utils/_common.py	Simplify typing imports and convert some generics to PEP 695 syntax.
model/common/src/icon4py/model/common/type_alias.py	Convert anyfloat alias to type statement and add UP040 suppression where needed.
model/common/src/icon4py/model/common/states/utils.py	Add UP040 suppressions for TypeAlias uses.
model/common/src/icon4py/model/common/states/model.py	Convert multiple TypeAlias declarations to type statements.
model/common/src/icon4py/model/common/model_backends.py	Convert backend aliases to type statements; retain runtime TypeAlias where used with isinstance().
model/common/src/icon4py/model/common/io/writers.py	Use stdlib typing.Required instead of typing_extensions.
model/common/src/icon4py/model/common/io/io.py	Switch enum to enum.StrEnum.
model/common/src/icon4py/model/common/grid/gridfile.py	Switch enum to enum.StrEnum.
model/common/src/icon4py/model/common/grid/grid_manager.py	Convert TypeAlias declarations to type statements.
model/common/src/icon4py/model/common/field_type_aliases.py	Add UP040 suppressions for TypeAlias uses.
model/common/src/icon4py/model/common/decomposition/definitions.py	Convert stream-like alias to type statement.
model/common/pyproject.toml	Bump minimum Python to 3.12 and drop typing-extensions dependency.
model/atmosphere/subgrid_scale_physics/muphys/pyproject.toml	Bump minimum Python to 3.12.
model/atmosphere/subgrid_scale_physics/microphysics/pyproject.toml	Bump minimum Python to 3.12.
model/atmosphere/dycore/pyproject.toml	Bump minimum Python to 3.12.
model/atmosphere/diffusion/pyproject.toml	Bump minimum Python to 3.12.
model/atmosphere/advection/pyproject.toml	Bump minimum Python to 3.12.
ci/benchmark_bencher_baseline.yml	Minor formatting (blank line).
ci/base.yml	Minor formatting (blank line).
bindings/src/icon4py/bindings/muphys_wrapper.py	Add a targeted type: ignore[arg-type] for graupel.Q(...).
bindings/src/icon4py/bindings/grid_wrapper.py	Convert annotated array aliases to type statements.
bindings/src/icon4py/bindings/dycore_wrapper.py	Convert annotated array aliases to type statements.
bindings/src/icon4py/bindings/common.py	Convert many annotated array aliases to type statements.
bindings/pyproject.toml	Bump minimum Python to 3.12.
.python-version	Set default dev Python version to 3.12.
.github/workflows/icon4py-test-tools-and-bindings.yml	Update CI Python matrix to 3.12/3.13/3.14.
.github/workflows/icon4py-test-model.yml	Update CI Python matrix to 3.12/3.13/3.14.
.github/workflows/deploy-docs.yml	Use Python 3.12 for docs build job.

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