fix(build): Find release branches correctly (#4844)
fix(build): Find release branches correctly (#4844)

Use `refs/heads/release/` instead of `release` when comparing against `github.ref` to see if size-check should be run.

Needed to unblock next release.
getsentry/raven-js,getsentry/raven-js,getsentry/raven-js,getsentry/raven-js