v21.2.12
refactor(aria/accordion): simplify code by using template references instead of user id to match panels with triggers (#32855)
fix(cdk/tree): enter/space key on child node should not toggle parent node expansion (#33125)
build: update `aspect_rules_js` to `3.0.2` (#32910)
fix(material/stepper): allow stepper to be labelled (#33137)
build: update public API golden infra and move to `goldens/`
build: set up API goldens for aria (#32441)
refactor(cdk/scrolling): remove circular dependencies
switch progress-spinner implementation to use MDC (#25324)