Update version number to `v3.0` #8738

Job	Run time
pre-flight-check	1m 37s
build-test-macos-with-address-sanitizer	7m 20s
build-test-ubuntu-32-bit	14m 17s
build-test-ubuntu	14m 22s
build-test-ubuntu-32-64-bit-mix-mode	18m 56s
build-test-ubuntu-bazel	15m 56s
build-test-ubuntu-with-address-sanitizer-gcc-latest	12m 7s
build-test-ubuntu-with-address-sanitizer-clang-latest	11m 57s
build-test-ubuntu-with-thread-sanitizer-clang-latest	12m 15s
build-test-unix-with-freebsd	14m 54s
build-test-windows-32-bit	9m 6s
build-test-windows-mingw	18m 6s
build-test-windows-msvc	9m 12s
check-status-of-nightly-action	11s
coverage-and-docs	28m 45s
run-integration-test	10m 24s
	3h 19m 25s

Provide feedback