v21.2.9
perf(cdk-experimental/column-resize): add debounce to column header hover to prevent excessive handler rendering (#30709)
refactor(cdk-experimental/popover-edit): fix strict property initialization errors
refactor(cdk-experimental/scrolling): fix strict property initialization errors
refactor(cdk-experimental/selection): fix strict property initialization errors
refactor(cdk-experimental/table-scroll-container): fix strict property initialization errors
build: update to TypeScript 5.9 (#31604)
docs: add README files for experimental packages (#15933)
build: create angular aria package (#31942)
docs: replace angular.io links with angular.dev (#29734)
build: clean-up to use fine-grained targets for faster rebuilds
build: remove deprecated compiler option (#32692)