docs: release notes for the v19.2.21 release #9824

Job	Run time
build-e2e-windows	3m 8s
lint	2m 2s
build	3m 9s
e2e-windows (24, webpack, 0)	4m 23s
e2e-windows (24, webpack, 2)	4m 23s
e2e-windows (24, esbuild, 4)	4m 24s
e2e-windows (24, esbuild, 2)	4m 23s
e2e-windows (24, webpack, 1)	4m 22s
e2e-windows (24, webpack, 5)	4m 25s
e2e-windows (24, webpack, 3)	4m 22s
e2e-windows (24, esbuild, 3)	4m 22s
e2e-windows (24, webpack, 4)	4m 23s
e2e-windows (24, esbuild, 1)	4m 23s
e2e-windows (24, esbuild, 0)	4m 23s
e2e-windows (24, esbuild, 5)	4m 23s
test	4m 25s
Browser Compatibility Tests	4m 25s
publish-snapshots	4m 24s
e2e-snapshots	1s
e2e-package-managers	1s
e2e	1s
	1h 14m 12s

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