Pin dependencies in workflows

[Zeitsperre]

Pull Request Checklist:

• This PR addresses an already opened issue (for bug fixes / features)
  • This PR fixes #xyz
• Tests for the changes have been added (for bug fixes / features)
  • (If applicable) Documentation has been added / updated (for bug fixes / features)
• CHANGES.rst has been updated (with summary of main changes)
  • Link to issue (:issue:number) and pull request (:pull:number) has been added

What kind of change does this PR introduce?

• Pins the dependencies of pip-related packages in GitHub Workflows
• Synchronizes more dependencies between configs
• Adds the latest coveralls (supports Python3.12)

Does this PR introduce a breaking change?

No.

Other information:

Pinning dependencies in GitHub Workflows is a suggestion from the Security Hardening linter. (see: https://github.com/ossf/scorecard/blob/49c0eed3a423f00c872b5c3c9f1bbca9e8aae799/docs/checks.md#pinned-dependencies)

[github-actions]

Note
It appears that this Pull Request modifies the main.yml workflow.

On inspection, the XCLIM_TESTDATA_BRANCH environment variable is set to the most recent tag (v2023.12.14).

No further action is required.

[SarahG-579462]

All looks fine to me, unless you need me to test the workflows are compatible with all this.

[coveralls]

coverage: 90.833%. first build
when pulling 5fb3c58 on pin-workflows
into 3d6c310 on main.