QNode.execute_kwargs no longer has mcm_config key

[andrijapau]

Context:

PennyLaneAI/pennylane#6807 deprecates mcm_config as an argument to qml.execute. Instead it is designed to have signature parity with QNode, instead accepting both postselect_mode and mcm_method as arguments and creating a MCMConfig internally.

❗ As a side-effect, QNode.execute_kwargs no longer has a mcm_config key.

This PR updates Catalyst source code to reflect that.

Description of the Change:

Use postselect_mode and mcm_method keys for QNode.execute_kwargs instead of mcm_config.

Benefits: Signature parity with QNode and better testing capabilities.

Possible Drawbacks: None identified.

[sc-80541]

[dime10]

Thanks @andrijapau !

[github-actions]

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Please edit doc/releases/changelog-dev.md on your branch with:

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[andrijapau]

@dime10, does this need to be in the changelog? 🙇🏼‍♂️

[dime10]

@dime10, does this need to be in the changelog? 🙇🏼‍♂️

It's alright from my side, but if you want to add it you can do it in the Internal Changes :)