Bump version to "v20.0.0" with changelog. #5992

Job	Run time
analyze	5s
build	4m 21s
lint	2m 44s
e2e-windows-subset	11m 17s
e2e-package-managers (ubuntu-latest, 22, yarn, 0)	7m 11s
e2e-package-managers (ubuntu-latest, 22, yarn, 1)	5m 24s
e2e-package-managers (ubuntu-latest, 22, pnpm, 0)	5m 46s
e2e-package-managers (ubuntu-latest, 22, pnpm, 1)	4m 36s
e2e-package-managers (ubuntu-latest, 22, pnpm, 2)	5m 34s
test	3m 13s
e2e (ubuntu-latest, 22, npm, 1)	11m 12s
e2e (ubuntu-latest, 22, npm, 4)	7m 51s
e2e (ubuntu-latest, 22, npm, 2)	10m 46s
e2e (ubuntu-latest, 22, npm, 0)	10m 20s
e2e (ubuntu-latest, 22, npm, 5)	9m 17s
e2e-package-managers (ubuntu-latest, 22, yarn, 2)	6m 22s
e2e (ubuntu-latest, 22, esbuild, 1)	9m 11s
e2e (ubuntu-latest, 22, npm, 3)	8m 52s
e2e (ubuntu-latest, 22, esbuild, 0)	6m 57s
e2e (ubuntu-latest, 22, esbuild, 2)	10m 20s
e2e (ubuntu-latest, 22, esbuild, 3)	8m 15s
e2e (ubuntu-latest, 22, esbuild, 4)	6m 47s
e2e (ubuntu-latest, 22, esbuild, 5)	6m 50s
e2e-snapshots	-1s
	2h 43m 10s

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