ci: update super linter version (v5 -> v7)

[davmacario]

Closes #44

📑 Description

Update Super Linter from version 5(slim) to version 7(slim).
Also formatted the .github/workflows/linter.yml file.

✅ Checks

• My pull request adheres to the code style of this project
• My code requires changes to the documentation
• I have updated the documentation as required
• All the tests have passed

ℹ Additional Information

N.A.

[gmacario]

@davmacario thank you for your contribution. Unfortunately it looks like additional changes are needed to make the build green:

[davmacario]

Unfortunately it looks like additional changes are needed to make the build green

Yep, I'm creating some config files for the linters - stuff like JSCPD uses default configuration values that are causing issues.

[davmacario]

I also realized that for how GitHub Actions are configured (triggered on push - for non-main branches - and on PR), this causes 2 actions to run at the same time when pushing to a branch for which there is a PR open.

Is this wanted?

[davmacario]

@gmacario the checks are now passed.

I chose to remove some of the linters because I deemed them "too much" for this project - let me know if you have any feedback on this.

Also, let me know about the problem with duplicate jobs.

[davmacario]

To solve the duplicate job issue, I propose something like:

job:
    lint:
        ...
        if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.repository
        ...

[gmacario]

To solve the duplicate job issue, I propose something like:

LGTM. Maybe you could file the duplicate runs as a separate bug, then create another PR 😉

[davmacario]

I will also improve the devcontainer setup - maybe with automatic pip package installations upon launch.