Fix Julia 1.10 compatibility bounds

[ohno]

@MartinMikkelsen I would like to fix this for JuliaFewBody/TwoBody.jl#38.

Summary

This PR restores Julia 1.10 compatibility and adds Julia 1.10 to the CI matrix. No runtime implementation is changed.

Background

This issue was discovered while integrating TensorTrainNumerics.dmrg_eigsolve into the QTT solver proposed in JuliaFewBody/TwoBody.jl#38, which addresses JuliaFewBody/TwoBody.jl#26.

Although TensorTrainNumerics.jl declares Julia 1.10 compatibility, its compatibility bounds required the Julia 1.11 versions of the Random and Test standard libraries. Consequently, dependency resolution failed on Julia 1.10 before any package tests could run.

After relaxing those bounds, the test environment still could not resolve on Julia 1.10 because the permitted JET versions, 0.11 and 0.12, require newer dependencies. JET 0.9 remains compatible with Julia 1.10.

Changes

• Relax the Random and Test compatibility bounds from 1.11.0 to 1.10.
• Allow JET 0.9 for the Julia 1.10 test environment while retaining JET 0.11 and 0.12 for newer Julia versions.
• Add Julia 1.10 to the GitHub Actions test matrix to prevent regressions.

Validation

The changes were tested locally with Julia 1.10.10.

• Package dependency instantiation succeeds.
• Loading TensorTrainNumerics succeeds.
• The focused DMRG test suite passes all 34 tests.
• A full package test proceeded past dependency resolution and entered initial compilation. The compilation did not finish within the local 15-minute test window, so the focused DMRG suite is the completed test result reported here.

This change should allow downstream packages to support Julia 1.10 consistently with the compatibility declared by TensorTrainNumerics.jl.

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This pull request was developed with assistance from Codex using GPT-5.6 Sol with High reasoning effort.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.42%. Comparing base (c5d2b10) to head (b19eb8f).

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #61   +/-   ##
=======================================
  Coverage   97.42%   97.42%           
=======================================
  Files          18       18           
  Lines        3721     3723    +2     
=======================================
+ Hits         3625     3627    +2     
  Misses         96       96           

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