Merge branch 'jk/test-lsan-denoise-output' into maint-2.42

Tests with LSan from time to time seem to emit harmless message
that makes our tests unnecessarily flakey; we work it around by
filtering the uninteresting output.

* jk/test-lsan-denoise-output:
  test-lib: ignore uninteresting LSan output

diff --cc t/test-lib.sh
Simple merge