chore: Add MAVEN_SERVER_ID for maven publishing

[oarbusi]

Proposed changes

Add MAVEN_SERVER_ID for maven publishing

Link to any related issue(s): CLOUDP-323824

Type of change:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as
  expected)
• This change requires a documentation update

Required Checklist:

• I have signed the MongoDB CLA
• I have added tests that prove my fix is effective or that my feature works
• I have added any necessary documentation (if appropriate)
• I have run make fmt and formatted my code
• I have tested the CDK constructor in a CFN stack. See TESTING.md
• If changes include removal or addition of 3rd party GitHub actions, I updated our internal document. Reach out to the APIx Integration slack channel to get access to the internal document.

Further comments

[Copilot]

Pull Request Overview

This PR introduces the MAVEN_SERVER_ID variable to the release workflow to support maven publishing.

• Adds a new environment variable MAVEN_SERVER_ID to the release job.
• Adjusts the workflow configuration to include this new variable.

Comments suppressed due to low confidence (1)

.github/workflows/release.yml:124

• The new environment variable MAVEN_SERVER_ID is sourced from vars while similar credentials are sourced from secrets. Please verify if this discrepancy is intentional or if it should be consistently sourced from secrets.

          MAVEN_SERVER_ID: ${{ vars.MAVEN_SERVER_ID }}

[andreaangiolillo]

LGTM