release: cut the v20.3.21 release #3278

Job	Run time
list	27s
workflow (modules-builder-tests)	1m 54s
workflow (build-unit-tests)	2m 37s
workflow (build-cli)	1m 30s
workflow (devkit-core-tests-rerun)	1m 26s
workflow (devkit-core-tests)	1m 20s
	9m 14s

Provide feedback