[v9_16] Run respdiff also for scheduled and web pipelines
respdiff needs to be run regularly to identify problems with query responses discrepancies sooner than after tagging a release.
Contrary to the main branch, which hosts the BIND 9 Development Version and thus sets MAX_DISAGREEMENTS_PERCENTAGE variable to 0.5, branches hosting BIND 9 Stable Versions have it set to 0.1, which provides only tiny room for non-timeout response disagreements between the baseline version and version under test.
(cherry picked from commit 561b5819)
Closes #2473 (closed)