Remove CPhase gate alias references

[sergei-mironov]

Context: Transition to the quantum device config schema 2

Description of the Change:

• Remove mentions of CPhase "gate" which happens to be a Python alias for ControlledPhaseShift.
• Remove the Python-only Projector patch because we already have a relaxed validation procedure for observables
• Relax operation validation by allowing kokkos device to declare C(GlobalPhase) which is a Python-only operation.

Benefits:
Possible Drawbacks:
Related GitHub Issues:

• Update device toml specs to schema 2 pennylane-lightning#642
  • (related discussion) Update device toml specs to schema 2 pennylane-lightning#642 (comment)

[codecov]

Codecov Report

Attention: Patch coverage is 60.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 98.04%. Comparing base (2636257) to head (69a24ab).
Report is 183 commits behind head on main.

Files	Patch %	Lines
frontend/catalyst/device/qjit_device.py	60.00%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #718      +/-   ##
==========================================
- Coverage   98.07%   98.04%   -0.03%     
==========================================
  Files          70       69       -1     
  Lines        9601     9536      -65     
  Branches      756      762       +6     
==========================================
- Hits         9416     9350      -66     
  Misses        151      151              
- Partials       34       35       +1     

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[dime10]

This can be closed right? My bad I thought this was just about the CPhase gate.

[sergei-mironov]

This can be closed right? My bad I thought this was just about the CPhase gate.

Even for CPhase, we need to remove it from tomls contained in the Catalyst repo too.

[erick-xanadu]

After #745 is merged and this PR is updated, one should run latest/latest/latest on this branch. I expect it to succeed. On #745 latest/latest/latest fails with the error message:

FAILED frontend/test/pytest/test_transform.py::TestBroadcastExpand::test_expansion_qnode_no_cache[lightning.kokkos-obs1-params2] - catalyst.utils.exceptions.CompileError: Gates in qml.device.operations and specification file do not match.
Gates that present only in the device: {'C(GlobalPhase)'}
Gates that present only in spec: set()

I am not asking for this to fix latest/latest/latest but merely to report what the outcome is on the channel so that we can fix it if this is not the case.

[erick-xanadu]

Since PR #745 might interfere with this PR I am just going to approve it now. But I will leave it to @dime10 to continue this review. I don't want to block this unnecessarily long. Cheers!

I never actually reviewed it, just made the suggestion that it should fix the other issue.

[sergei-mironov]

After #745 is merged and this PR is updated, one should run latest/latest/latest on this branch. I expect it to succeed. On #745 latest/latest/latest fails with the error message:

FAILED frontend/test/pytest/test_transform.py::TestBroadcastExpand::test_expansion_qnode_no_cache[lightning.kokkos-obs1-params2] - catalyst.utils.exceptions.CompileError: Gates in qml.device.operations and specification file do not match.
Gates that present only in the device: {'C(GlobalPhase)'}
Gates that present only in spec: set()

I am not asking for this to fix latest/latest/latest but merely to report what the outcome is on the channel so that we can fix it if this is not the case.

@erick-xanadu I merged this PR with the recent main and solved the conflicts. The test you mentioned should pass now.