Python binary path added to Environment Variable Path on Windows causes conflict with WebGL Build Tools

1. What happened

When attempting to make WebGL build i got the following error:

File "C:\tools\python\lib\site.py", line 176
file=sys.stderr)
^
SyntaxError: invalid syntax

2. How we can reproduce it using the example you attached
a. Set path to a custom Python installation, such that python.exe is in the path and accessible from e.g. the command line (edit system environment variables > system variables > Path > add e.g. ;c:\tools\python;)

b. Launch Unity Editor after the change to the path variable.

c. Make a WebGL build