More sophisticated measurement validation for default-qubit

[astralcai]

Description of the Change: Add measurement-specific observable validations to measurement validation

[sc-64700]

[github-actions[bot]]

Hello. You may have forgotten to update the changelog! Please edit doc/releases/changelog-dev.md with:

• A one-to-two sentence description of the change. You may include a small working example for new features.
• A link back to this PR.
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[codecov[bot]]

Codecov Report

Attention: Patch coverage is 96.77419% with 1 line in your changes missing coverage. Please review.

Project coverage is 99.63%. Comparing base (8fec135) to head (51b0996). Report is 2 commits behind head on master.

Files	Patch %	Lines
pennylane/devices/default_qubit.py	96.77%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #5890 +/- ## ========================================== - Coverage 99.67% 99.63% -0.04% ========================================== Files 422 425 +3 Lines 40651 40484 -167 ========================================== - Hits 40518 40338 -180 - Misses 133 146 +13 ```

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