Dotty

Make `caps.Capability` non-experimental #36799

Job	Run time
test	1h 8m 8s
test_windows_fast	34m 46s
test_non_bootstrapped	0s
build-msi-package	0s
community_build_a	45m 11s
test_windows_full	0s
test_sbt	20m 14s
MiMa	9m 48s
test_scala2_library_tasty	0s
community_build_b	1h 17m 59s
community_build_c	1h 3m 28s
test_java8	0s
build-sdk-package / build	10m 17s
test-msi-package	0s
build-chocolatey-package / build	24s
test-chocolatey-package	0s
publish_nightly	0s
publish_release	0s
nightly_documentation	0s
open_issue_on_failure	0s
	5h 30m 15s

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