Bump semver and @actions/github

Removes [semver](https://github.com/npm/node-semver). It's no longer used after updating ancestor dependency [@actions/github](https://github.com/actions/toolkit/tree/HEAD/packages/github). These dependencies need to be updated together.


Removes `semver`

Updates `@actions/github` from 2.1.1 to 5.1.1
- [Changelog](https://github.com/actions/toolkit/blob/main/packages/github/RELEASES.md)
- [Commits](https://github.com/actions/toolkit/commits/HEAD/packages/github)

---
updated-dependencies:
- dependency-name: semver
  dependency-type: indirect
- dependency-name: "@actions/github"
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]