Bump version to "v20.3.20" with changelog. #12444

Job	Run time
build-e2e-windows-subset	6m 24s
analyze	6s
build	6m 12s
lint	2m 39s
test	3m 41s
e2e-package-managers (ubuntu-latest, 22, yarn, 2)	7m 20s
e2e-package-managers (ubuntu-latest, 22, pnpm, 1)	5m 8s
e2e-package-managers (ubuntu-latest, 22, yarn, 1)	6m 26s
e2e-package-managers (ubuntu-latest, 22, pnpm, 2)	5m 42s
e2e (ubuntu-latest, 22, npm, 1)	9m 25s
e2e-package-managers (ubuntu-latest, 22, yarn, 0)	8m 9s
e2e-package-managers (ubuntu-latest, 22, pnpm, 0)	5m 58s
e2e (ubuntu-latest, 22, npm, 4)	8m 49s
e2e (ubuntu-latest, 22, npm, 2)	10m 8s
e2e (ubuntu-latest, 22, npm, 0)	11m 39s
e2e (ubuntu-latest, 22, npm, 3)	8m 17s
e2e (ubuntu-latest, 22, esbuild, 2)	8m 55s
e2e (ubuntu-latest, 22, esbuild, 5)	6m 59s
e2e (ubuntu-latest, 22, esbuild, 3)	9m 24s
e2e (ubuntu-latest, 22, npm, 5)	12m 6s
e2e (ubuntu-latest, 22, esbuild, 4)	6m 30s
e2e (ubuntu-latest, 22, esbuild, 1)	10m 11s
e2e (ubuntu-latest, 22, esbuild, 0)	9m 9s
e2e-snapshots	0s
e2e-windows-subset	3m 48s
	2h 53m 5s

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