chore(NODE-5382): add 4.x release workflow

[nbbeeken]

Description

What is changing?

• Copied the release from main workflow
• Changed the branch trigger to 4.x
• Changed default-branch to 4.x
• added npm tag "4x"

Is there new documentation needed for these changes?

No

What is the motivation for this change?

Automagic releases for 4.x

Release Highlight

Double check the following

• [/] Ran npm run check:lint script
• Self-review completed using the steps outlined here
• PR title follows the correct format: type(NODE-xxxx)[!]: description
  • Example: feat(NODE-1234)!: rewriting everything in coffeescript
• [/] Changes are covered by tests
• [/] New TODOs have a related JIRA ticket

[nbbeeken]

Depends on #3747, that PR just copies the scripts to 4.x so that release_notes workflow has access to them when it checks out the release PR which was branched from 4.x not main

[durran]

Same as regular release workflow with branches changed.