Migrate CI to centralized SciML reusable workflows

[ChrisRackauckas-Claude]

Please ignore until reviewed by @ChrisRackauckas.

Normalizes CI toward the SciML centralized reusable-workflow standard (SciML/.github, all callers pinned @v1).

Workflows converted to centralized callers

• Documentation.yml -> documentation.yml@v1 (coverage on, matching the original --code-coverage=user + Codecov upload; the original fail_ci_if_error: true is not replicated by the central workflow).
• FormatCheck.yml (Runic) -> runic.yml@v1. The repo already ran fredrikekre/runic-action@v1, so the code is already Runic-formatted; no formatting changes were needed/applied.
• SpellCheck.yml -> spellcheck.yml@v1 (typos; central pins v1.47.0, up from v1.18.0).

Removed

• CompatHelper.yml deleted (replaced by Dependabot's julia ecosystem updates).

Left unchanged

• CI.yml: NOT converted. The test job runs inside the Docker container cmhyett/julia-fenics:latest because the FEniCS test suite requires a system Python FEniCS install. The centralized tests.yml@v1 has no container: support, so converting would break the tests. Preserved verbatim (matrix: group=[Core], version=[lts,1,pre], no coverage).
• TagBot.yml: unchanged (registered package).

Not added (and why)

• Downgrade: intentionally NOT added. downgrade.yml@v1 runs the full test suite on a stock ubuntu-latest with no FEniCS container, which would fail every run for this package. Adding it would create a permanently-red required check. Same container blocker as Tests.
• Downstream / Benchmark / QA: none existed; not invented.

Dependabot

• Removed the crate-ci/typos ignore block (standing policy: keep everything current).
• Preserved the existing github-actions (weekly) and julia / (daily, grouped) blocks.
• Added a julia block for /docs (which has its own Project.toml) to keep its compat updated after CompatHelper removal. (/test has no Project.toml; it uses [extras]/[targets], so no block needed.)

Typos findings

• Ran typos locally (v1.34.0): clean, no findings. No _typos.toml added.

Heads-up for branch protection

Check names change with this migration (e.g. the Runic job is now Runic Format Check, spellcheck is Spell Check with Typos, docs is Build and Deploy Documentation). Any required-status-checks in branch protection must be updated to the new names.

🤖 Generated with Claude Code