add py3.12, drop py3.7, pyupgrade 3.8+ #51

Job	Run time
Build the documentation	23s
Python: 3.8-x64 on ubuntu-latest	31s
Lint the package	39s
Validate coverage	32s
Python: 3.8-x64 on windows-latest	1m 41s
Python: 3.8-x86 on windows-latest	1m 26s
Python: 3.8-x64 on macos-latest	35s
Python: 3.9-x64 on ubuntu-latest	25s
Python: 3.9-x64 on windows-latest	1m 3s
Python: 3.9-x86 on windows-latest	1m 6s
Python: 3.9-x64 on macos-latest	31s
Python: 3.10-x64 on ubuntu-latest	25s
Python: 3.10-x64 on windows-latest	1m 22s
Python: 3.10-x86 on windows-latest	1m 34s
Python: 3.10-x64 on macos-latest	40s
Python: 3.11-x64 on ubuntu-latest	25s
Python: 3.11-x64 on windows-latest	1m 28s
Python: 3.11-x86 on windows-latest	1m 36s
Python: 3.11-x64 on macos-latest	33s
Python: 3.12-x64 on ubuntu-latest	34s
Python: 3.12-x64 on windows-latest	1m 25s
Python: 3.12-x86 on windows-latest	1m 38s
Python: 3.12-x64 on macos-latest	43s
Python: pypy-3.8-x64 on ubuntu-latest	56s
Python: pypy-3.8-x64 on macos-latest	1m 13s
	23m 24s

Provide feedback