Rename "OS X" to "macOS"

We should go over our projects and rename every "OS X" instance to "macOS". Apple changed the name in 2016 with 10.12 (which is the minimum supported version after ESR 78) and there is macOS 11 in beta (thus no X anymore). Thanks to a cypherpunk for pointing that out.

mentioned in issue tor-browser#40049 (closed)

added Backlog label

removed Backlog label

added Next label

added temp label

added Roadmap::Future label and removed Next label

added Next Q2 labels and removed Roadmap::Future temp labels

added Backlog label and removed Next label

added Q3 label and removed Q2 label

removed Q3 label

changed milestone to %Sponsor 131 - Phase 5 - Ongoing Maintenance

added MacOS Sponsor 131 labels

mentioned in issue tor-browser#40111 (closed)

mentioned in merge request !520 (merged)

marked this issue as related to #40439 (closed)

removed Backlog label

added Roadmap::Future label

mentioned in merge request !566 (merged)

marked this issue as related to #40668 (closed)

closed with merge request !566 (merged)

mentioned in issue tor-browser-bundle-testsuite#40064 (closed)

marked this issue as related to tor-browser-bundle-testsuite#40064 (closed)

mentioned in merge request tor-browser-bundle-testsuite!27 (merged)