Proposed changes

This PR updates the FOAS release process to include the changelog

Jira ticket: CLOUDP-266445

Release process changes:

Updated the release runner to provide the env where to release the spec/changelog when running the action manually
Added a changelog workflow that runs after the FOAS has been merged into the repo
- Download the base folder containing changelog and specs before the foas release
- Download the exemption file from the s3 bucket
- Run foascli changelog command and commit the generated changelog.

This PR also add the changelog from evergreen vbranch that we need to append new entries on top it. I tested my changes in fork https://github.com/andreaangiolillo/openapi-test/actions/runs/10508717157

Next steps:

I will tests the release process in the repo as well. I will need to push the current changelog from the vbranch.