man.sr.ht: overhaul init files

man.sr.ht: add py3-scmsrht dependency

man.sr.ht: normalize init scripts

Add py3-yaml to man.sr.ht dependencies

Add -openrc to man.sr.ht

Update man.sr.ht.post-upgrade

Also moves alembic dependency to py3-srht

Update man.sr.ht.init

Add man.sr.ht package