docs: release notes for the v19.2.21 release #3045

Job	Run time
list	20s
workflow (modules-builder-tests)	2m 10s
workflow (devkit-core-tests)	1m 26s
workflow (build-unit-tests)	2m 29s
workflow (build-cli)	1m 51s
workflow (devkit-core-tests-rerun)	1m 31s
	9m 47s

Provide feedback