[Backport 1.6.latest] Hotfix for 372: Use JSONEncoder in json.dumps #15751

Job	Run time
code-quality	2m 11s
unit test / python 3.8	2m 0s
unit test / python 3.9	1m 40s
unit test / python 3.10	1m 53s
unit test / python 3.11	1m 33s
integration test / python 3.8 / ubuntu-20.04	23m 14s
integration test / python 3.9 / ubuntu-20.04	25m 1s
integration test / python 3.10 / ubuntu-20.04	29m 20s
integration test / python 3.11 / ubuntu-20.04	27m 27s
integration test / python 3.8 / windows-latest	32m 20s
integration test / python 3.8 / macos-latest	22m 8s
build packages	51s
	2h 49m 38s

Provide feedback