Attempt to fix CI.

[abizjak]

Purpose

Fix actions so that the contracts-common actions actually run.

Also avoid using obsolete actions-rs actions and update checkout action to avoid warnings about obsolete versions.

Checklist

• My code follows the style of this project.
• The code compiles without warnings.
• I have performed a self-review of the changes.
• I have documented my code, in particular the intent of the
  hard-to-understand areas.
• (If necessary) I have updated the CHANGELOG.