fix: find first associate pull request (#764)
fix: find first associate pull request (#764)

Co-authored-by: Benjamin E. Coe <69440dae14aaa9fe2429b324bfce03449d09e1db@google.com>
googleapis/release-please,googleapis/release-please,googleapis/release-please,googleapis/release-please,googleapis/release-please,googleapis/release-please,googleapis/release-please