[build.webkit.org Rename slave to worker in steps.py. This is for two purposes: 1) Preparing to upgrade buildbot 2) Using more inclusive naming Similar to https://trac.webkit.org/r268429
<rdar://problem/70384869>
Created attachment 411598 [details] Patch
Committed r268601: <https://trac.webkit.org/changeset/268601> All reviewed patches have been landed. Closing bug and clearing flags on attachment 411598 [details].