Automatically generate changelog updates from commits

Summary

• Copied ReleaseNotes.md into CHANGELOG.md and ensured the format is consistent. The CHANGELOG.md does not include the changes for the next version.
• ReleaseNotes.md will remain until the next release in which we no longer use it.
• Adds a pipeline stage changelog which allows for the preview and updating of the CHANGELOG.md through an MR.
• Added a pipeline job that will upload the release to GitLab after the release_public_rpm job has been triggered.
• Moved deploy-eos.sh to release/upload_to_eos.sh to make the name more descriptive and consistent, and to group it logically with the rest of the release-related scripts
• Added an access token ci-gitlab-api (https://gitlab.cern.ch/cta/CTA/-/settings/access_tokens)
• Added a CI/CD variable CI_API_TOKEN that uses the access token so that the ci runner can use the GitLab API (https://gitlab.cern.ch/cta/CTA/-/settings/ci_cd)

An example of what the MR looks like in a fork of CTA can be found here: https://gitlab.cern.ch/nbugel/CTA/-/merge_requests/1

Additional Required Actions

• Requires manual tests in pre-production: NO

• Requires a documentation update: YES #795 (closed)

References

Closes #782 (closed) Closes #780 (closed)