You could try the next workaround:
Create in the
C:\ProgramData\checkmk\agent\modules\python-3\DLLs\
file
python._pth
with content
C:\ProgramData\checkmk\agent\modules\python-3\DLLs
C:\ProgramData\checkmk\agent\modules\python-3\lib
C:\ProgramData\checkmk\agent\modules\python-3
C:\ProgramData\checkmk\agent\modules\python-3\lib\site-packages
import site
Underscore in extension, i.e. ._pth
is important. At least in my test environment with Python 3.10