Pin workflows to a specific version

[bkhouri]

Pin the workflows to a specific version to ensure stability and consistency across runs.

Also, add a dependabot.yml file to automatically update the shared workflows when a new release is available.

Checklist

• [x] I've added at least one test that validates that my change is working, if appropriate
• [x] I've followed the code style of the rest of the project
• [x] I've read the Contribution Guidelines
• [x] I've updated the documentation if necessary