Update T8code requirement from 0.7.6 to 0.7.6, 0.9 in the all-julia-dependencies group across 1 directory

[dependabot]

Updates the requirements on T8code to permit the latest version.
Updates T8code to 0.9.0

Release notes

Sourced from T8code's releases.

v0.9.0

T8code v0.9.0

Diff since v0.8.0

Breaking changes

• The t8_forest_leaf_face_neighbors and t8_forest_leaf_face_neighbors_ext functions have undergone a major update, see https://github.com/DLR-AMR/t8code/blob/main/NEWS.md#user-updates-for-the-upcoming-t8code-release-february-2026---version-format-unclear

Merged pull requests:

• Bump the all-github-actions group with 2 updates (#116) (@​dependabot[bot])
• t8code May release (#119) (@​benegee)

Closed issues:

• libsc crashes Julia when running the GC and using multiple threads (#35)

Commits

• 4399efb t8code May release (#119)
• 7885cc4 Bump the all-github-actions group with 2 updates (#116)
• a25cd10 t8code v4 / T8code.jl v0.8.0 (#115)
• See full diff in compare view

[github-actions]

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Testing

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.22%. Comparing base (c9f3657) to head (399b469).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3074      +/-   ##
==========================================
- Coverage   96.88%   94.22%   -2.66%     
==========================================
  Files         647      647              
  Lines       50035    50029       -6     
==========================================
- Hits        48475    47138    -1337     
- Misses       1560     2891    +1331     

Flag	Coverage Δ
unittests	94.22% <ø> (-2.66%)	⬇️

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