[Backport 1.8.latest] Drop support for Python 3.8 #21413

Job	Run time
code-quality	1m 8s
build packages	13s
unit test / python 3.9	1m 7s
unit test / python 3.10	1m 12s
unit test / python 3.11	1m 12s
verify packages / python 3.9 / ubuntu-latest	1m 3s
verify packages / python 3.10 / ubuntu-latest	58s
verify packages / python 3.11 / ubuntu-latest	1m 2s
verify packages / python 3.9 / macos-12	1m 41s
verify packages / python 3.10 / macos-12	1m 48s
verify packages / python 3.11 / macos-12	1m 18s
verify packages / python 3.9 / windows-latest	2m 35s
verify packages / python 3.10 / windows-latest	3m 28s
verify packages / python 3.11 / windows-latest	2m 46s
	21m 31s

Provide feedback