fix stable and latest CI

[josephleekl]

Context:
There are several issues causing our CIs to fail:

• Since we removed our requirements.txt files and have all dependencies specified in pyproject.toml, our stable CI tests have failed, as it cannot install the test dependencies with the same command.
• Since pytest 9.0 is introduced, one of test fixtures is deprecated and caused an error
• This uncovered one issue with PennyLane's queueing of matrix decomposition in a test
• This uncovered another issue with PennyLane's handling of wire_order in Composite Op

Description of the Change:

1. We introduce a temporary patch (which needs to be removed in the next release cycle) to install test dependencies with pip install -r requirements-tests.txt (the old way) for stable CI runs.

2. We updated the fixture to be compliant with pytest 9.0.For stable test, this is not reflected, so we pull the older version of pytest, which will also be removed in the next release cycle.

3. We apply the same fix applied before to an offending test in the mpitests

4. We update the argument type of wire_order in a test

Benefits:
stable/stable and latest/latest CIs both pass again.

Possible Drawbacks:

Related GitHub Issues:

[sc-110620]

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.83%. Comparing base (935644a) to head (d73f98b).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1340      +/-   ##
==========================================
- Coverage   95.58%   94.83%   -0.75%     
==========================================
  Files         243      187      -56     
  Lines       40039    28815   -11224     
==========================================
- Hits        38272    27328   -10944     
+ Misses       1767     1487     -280     

Flag	Coverage Δ
unit_tests	94.83% <100.00%> (-0.75%)	⬇️

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[JerryChen97]

Thanks for fixing!

[maliasadi]

Thanks @josephleekl!

Don't forget to update the changelog :)

[jzaia18]

Thanks for the fix, just don't forget to create a story for after the release