docs: release notes for the v20.3.0-rc.0 release #8615

Job	Run time
build	2m 43s
build-e2e-windows	3m 9s
lint	2m 12s
Browser Compatibility Tests	2m 31s
test	2m 32s
publish-snapshots	2m 32s
e2e-windows (windows-2025, 22, npm, 0)	2m 6s
e2e-windows (windows-2025, 22, esbuild, 1)	2m 6s
e2e-windows (windows-2025, 22, npm, 4)	2m 5s
e2e-windows (windows-2025, 22, npm, 1)	2m 5s
e2e-windows (windows-2025, 22, npm, 5)	1m 58s
e2e-windows (windows-2025, 22, npm, 3)	2m 6s
e2e-windows (windows-2025, 22, npm, 2)	2m 5s
e2e-windows (windows-2025, 22, esbuild, 4)	2m 6s
e2e-windows (windows-2025, 22, esbuild, 3)	2m 1s
e2e-windows (windows-2025, 22, esbuild, 5)	1m 49s
e2e-windows (windows-2025, 22, esbuild, 0)	2m 6s
e2e-windows (windows-2025, 22, esbuild, 2)	2m 7s
e2e-package-managers	1s
e2e-snapshots	1s
e2e	1s
	40m 22s

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