Improvements

Rook v1.6.9 s a patch release limited in scope and focusing on small feature additions and bug fixes.

Ceph

• Make storage device config nullable (#8552, @BlaineEXE)
• Build with latest golang v1.16.7 (#8540, @BlaineEXE)
• Refuse to failover the arbiter mon on stretch clusters (#8520, @travisn)
• Add an option to enable/disable merge all placement (#8381, @subhamkrai)
• Update ancillary monitoring resources (#8406, @BlaineEXE)
• Updated mon health check goroutine for reconfiguring patch values (#8370, @parth-gr)
• Releases for v1.6 are now based on Github actions instead of Jenkins (#8525 #8564, @subhamkrai)