.github/workflows: run integration test if event is a push

Run the integration tests if the event that triggered them is a push to
main. Previous changes to skip these tests on pull requests from forks
or dependabot had the unintended impact of disabling them on merges into
main.

Updates #cleanup

Signed-off-by: Mario Minardi <mario@tailscale.com>

Author: mpminardi

.github/workflows/test.yml

@@ -22,7 +22,7 @@ jobs:
     # the bot does not have credentials for the integration testing tailnet.
     # TODO(mpminardi): revisit / remove this if / when we give dependabot a tailnet for
     # testing with a smaller blast radius.
-    if: ${{ github.event.pull_request.head.repo.full_name == github.repository && github.actor != 'dependabot[bot]' }}
+    if: ${{ github.event_name == 'push' || (github.event.pull_request.head.repo.full_name == github.repository && github.actor != 'dependabot[bot]') }}
     name: ${{ matrix.os }} (${{ matrix.arch }}) (${{ matrix.credential-type }}) tailscale-${{ matrix.version }}
     strategy:
       fail-fast: false