format: add more information in os_type

From python3.8, platform.platform() changed the output:

$ python3.7 -c 'import platform ; print(platform.platform())'
Linux-5.10.0-16-amd64-x86_64-with-debian-11.4

$ python3.8 -c 'import platform ; print(platform.platform())'
Linux-5.10.0-16-amd64-x86_64-with-glibc2.2.5