Update to t8code v4.0.0-26-10

[benegee]

Update to t8code version currently pulled in via Trixi.jl.

This is bit difficult to track. Unlike #307 the latest T8code.jl release was not breaking for Trixi.jl, so it gets pulled in here as well, which however leads to an inconsistent state w.r.t. the t8code version we compile manually in CI.

Should we introduce compat bounds on T8code.jl or t8code_jll.jl?

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.11%. Comparing base (9a350ac) to head (0bf2244).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #321   +/-   ##
=======================================
  Coverage   96.11%   96.11%           
=======================================
  Files          25       25           
  Lines        1260     1260           
  Branches       74       74           
=======================================
  Hits         1211     1211           
  Misses         45       45           
  Partials        4        4           

Flag	Coverage Δ
unittests	96.11% <ø> (ø)

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[sloede]

LGTM!

[sloede]

Should we introduce compat bounds on T8code.jl or t8code_jll.jl?

This might make sense. It depends on how much hassle - i.e., need for manual intervention - it gives you because of version mismatches.