[ADAP-475] Update release to account for being in GHA

[emmyoop]

High Level Task

Now that we're in GitHub Actions, we can take advantage of the more automated release process! This should mostly be small tweaks and some docs cleanup.

Acceptance Criteria

• Update the comment in the release workflow
• Create and add a env_setup_script_path. See other adapters for examples of what's needed.
• Remove the Spark safety check here and here - Remove spark exception dbt-release#141
• Update the release notes in Notion here to reflect spark now having the same release as other adapters

Details

Testing will probably be the hardest part of this. When testing the release it generates a draft release and published to PyPI test.

Additional Notes

This change needs to be backported to 1.1.latest - 1.5.latest. Specifically the env-setup.sh is what needs to be backported. The release workflow itself is always run off main.