Bump version to v3.1.0 & add release notes (#480) #3623

Job	Run time
reusable_docker_tests / docker-test	32m 35s
reusable_tests / asan	3m 28s
reusable_tests / multiplatform-tests (Release, ubuntu-22.04)	3m 29s
reusable_tests / multiplatform-tests (Release, ubuntu-24.04)	3m 24s
reusable_tests / clang	1m 45s
reusable_tests / coverage	3m 32s
reusable_tests / multiplatform-tests (Release, windows-2019)	13m 58s
reusable_tests / multiplatform-tests (Release, windows-2022)	12m 56s
reusable_tests / multiplatform-tests (Debug, ubuntu-22.04)	3m 41s
reusable_tests / tsan	3m 43s
reusable_tests / flaky	1m 39s
reusable_tests / multiplatform-tests (Debug, ubuntu-24.04)	3m 35s
reusable_tests / multiplatform-tests (Debug, windows-2019)	12m 43s
reusable_tests / multiplatform-tests (Debug, windows-2022)	6m 52s
reusable_tests / docs	50s
reusable_tests / python-linter	16s
reusable_tests / uncrustify	37s
	1h 49m 3s

Provide feedback