kill-old-processes should be invoked with Python 3.
<rdar://problem/82397885>
Created attachment 436532 [details] Patch
rs=me would be good to test on staging instance.
Comment on attachment 436532 [details] Patch rs=me
Created attachment 436563 [details] Patch
Committed r281673 (241023@main): <https://commits.webkit.org/241023@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 436563 [details].
Restarted buildbot on EWS and build.webkit.org to pick up this change.