Remove test that checked that multi-controlled global-phase decomposition raises a warning

[joeycarter]

Context: A decomposition for multi-controlled global phases was recently added in PennyLane: PennyLaneAI/pennylane#6936. Catalyst contained a test test_global_phase_decomp_raises_warning that checked that such decompositions raise a warning. This test is therefore no longer needed and can be removed.

Description of the Change: Removes the test test_global_phase_decomp_raises_warning.

Benefits: This test is currently failing with PennyLane latest. Removing it will fix the pytest failure.

[github-actions]

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[maliasadi]

🙌

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.90%. Comparing base (6942e30) to head (62c99c7).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1522      +/-   ##
==========================================
+ Coverage   90.90%   95.90%   +5.00%     
==========================================
  Files          21       80      +59     
  Lines        1485     8336    +6851     
  Branches        0      779     +779     
==========================================
+ Hits         1350     7995    +6645     
- Misses        135      286     +151     
- Partials        0       55      +55     

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