release: cut the v21.0.0-rc.3 release #9204

Job	Run time
lint	2m 17s
build	2m 14s
build-e2e-windows	2m 33s
test	1m 3s
Browser Compatibility Tests	1m 4s
publish-snapshots	1m 3s
e2e-windows (windows-2025, 22, npm, 0)	37s
e2e-windows (windows-2025, 22, npm, 2)	38s
e2e-windows (windows-2025, 22, npm, 3)	37s
e2e-windows (windows-2025, 22, npm, 4)	38s
e2e-windows (windows-2025, 22, npm, 1)	38s
e2e-windows (windows-2025, 22, npm, 5)	38s
e2e-windows (windows-2025, 22, esbuild, 2)	39s
e2e-windows (windows-2025, 22, esbuild, 4)	39s
e2e-windows (windows-2025, 22, esbuild, 1)	37s
e2e-windows (windows-2025, 22, esbuild, 3)	37s
e2e-windows (windows-2025, 22, esbuild, 5)	35s
e2e-windows (windows-2025, 22, esbuild, 0)	39s
e2e-package-managers	1s
e2e-snapshots	1s
e2e	1s
	17m 49s

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