Do not run "make recheck" if the test suite fails

Running "make recheck" after the test suite fails hides intermittent system test failures in GitLab CI. This makes it hard to identify which branches are affected by a particular test failure mode and causes CI results to be overly optimistic. Prevent "make recheck" from being run when "make check" fails to ensure GitLab CI results properly reflect the stability of the "main" branch.