[BUG] GH Release changelog is creating broken diff links

[jasonkarns]

Describe the bug
The release process for this action is generating broken changelogs

To Reproduce
Steps to reproduce the behavior:

1. Visit https://github.com/actions/dependency-review-action/releases
2. Scroll to any release that has "full changelog" link
3. See the "from" portion of the diff link is v4 tag.

Expected behavior
The "Full Changelog" link should be generating a link from the prior version. So release https://github.com/actions/dependency-review-action/releases/tag/v4.8.1 should have a link of v4.8.0 to v4.8.1: v4.8.0...v4.8.1

Screenshots

Action version
na

Note: if you're not running the latest release please try that first!

Examples
na

Additional context
The problem here is because you're using a v4 tag to indicate the "latest release of v4 line". This violates git expectations for one, because it means the v4 tag is not immutable, but is instead being force-pushed every time there is a new release. Which breaks GitHub Releases, because the GH Release Notes assume that the full changelog should be from the "last/previous" tag, to the one being released. This is normally a safe assumption when following git guidelines. But the use of a continually-force-pushed vMAJOR tag violates those assumptions and breaks GH Releases.

The fix is simple: use a v4 branch instead of a tag. This way, whenever a release is cut, GH Releases is able to derive the "previous" tag correctly, and generate the release notes properly. Bonus points: you won't have to keep force-pushing a tag, and you align with git recommendations. (Branches are for continually-updated ref heads, not tags.)