Resolve intermittent 404s in Gitlab pipeline

Contains an update to @semantic-release/gitlab which resolves intermittent 404's in the Publish job of the Gitlab pipeline.

Pass default branch to semantic release

Semantic release doesn't recognize 'main' as a build branch unless we pass it, so using CI_DEFAULT_BRANCH here to pass directly from the gitlab-runner CLI.

Add to main branch

Run the pipeline on main as well as master