Bump version to "v20.3.9" with changelog. #9656

Job	Run time
lint	2m 41s
analyze	5s
build	5m 51s
build-e2e-windows-subset	6m 3s
test	3m 32s
e2e-package-managers (ubuntu-latest, 22, yarn, 2)	6m 41s
e2e-package-managers (ubuntu-latest, 22, pnpm, 0)	6m 9s
e2e-package-managers (ubuntu-latest, 22, yarn, 0)	8m 5s
e2e-package-managers (ubuntu-latest, 22, pnpm, 2)	5m 45s
e2e (ubuntu-latest, 22, npm, 0)	11m 10s
e2e-package-managers (ubuntu-latest, 22, pnpm, 1)	5m 36s
e2e (ubuntu-latest, 22, npm, 4)	9m 57s
e2e (ubuntu-latest, 22, npm, 1)	9m 0s
e2e (ubuntu-latest, 22, npm, 5)	12m 0s
e2e (ubuntu-latest, 22, esbuild, 1)	10m 0s
e2e (ubuntu-latest, 22, esbuild, 2)	9m 1s
e2e (ubuntu-latest, 22, esbuild, 3)	8m 40s
e2e (ubuntu-latest, 22, npm, 3)	8m 41s
e2e (ubuntu-latest, 22, npm, 2)	10m 24s
e2e (ubuntu-latest, 22, esbuild, 5)	7m 16s
e2e-package-managers (ubuntu-latest, 22, yarn, 1)	6m 6s
e2e (ubuntu-latest, 22, esbuild, 4)	6m 14s
e2e (ubuntu-latest, 22, esbuild, 0)	9m 21s
e2e-snapshots	0s
e2e-windows-subset	4m 34s
	2h 52m 52s

Provide feedback