"Rework CI for linting and use new linting in main CI"

[timfelle]

This pull request includes the following changes:

• Rework of the CI for linting, including separating linting into its own file, performing checks for the repository and all changed files individually, and adding the ability to set a minimum score when calling the action.

• Using the new linting in the main CI workflow.

• Clean up of the workflow.

These changes improve the linting process and make it more clear what can be done to improve it.

As an additional bonus, we now cancel old workflows for a PR when a new commit is submitted. which should help reduce resource usage and speedup return for the valid runs.

[timfelle]

@njansson One note with this one, the branch rules should be modified to include this PR.