[Frontend] Make tests toml-schema independent

[sergei-mironov]

Context: Transition to the quantum device config schema 2

Description of the Change: Solve a regarding toml schema 2 udpate in tests by switching our test custom devices from toml text manipulations to the device capability manipulations

Benefits:

• Tests no longer require toml text manipulations.
• Tests now contain simple examples of custom devices.
• toml-specific code is now locates in catalyst.utils.toml.

Possible Drawbacks:

Related GitHub Issues: https://github.com/PennyLaneAI/pennylane-lightning/pull/642

[dime10]

Good point, we could just make it compatible with both. I was just going to move to version 2 entirely once the PR is merged. I'm happy with this as well though.

Note there are several other tests that need this update though :)

[sergei-mironov]

Note there are several other tests that need this update though :)

@dime10 , are there? I think I changed the device which is used by several tests, and can't see other places.

[dime10]

Note there are several other tests that need this update though :)

@dime10 , are there? I think I changed the device which is used by several tests, and can't see other places.

Have a look at the test_decomposition and test_quantum_control lit tests

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 97.01493% with 4 lines in your changes missing coverage. Please review.

Project coverage is 98.07%. Comparing base (47b3482) to head (eadeb91). Report is 175 commits behind head on main.

Files	Patch %	Lines
frontend/catalyst/device/qjit_device.py	95.12%	2 Missing and 2 partials :warning:

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #712   +/-   ##
=======================================
  Coverage   98.07%   98.07%           
=======================================
  Files          70       70           
  Lines        9599     9601    +2     
  Branches      754      756    +2     
=======================================
+ Hits         9414     9416    +2     
  Misses        151      151           
  Partials       34       34           

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[sergei-mironov]

Have a look at the test_decomposition and test_quantum_control lit tests

@dime10 right, thanks! I have made these tests toml-independent. It required some further code reshaping, could you please review?