Remove use_default_shell_env

[aherrmann]

depends on #1136 change base branch before merging

• Remove all instances of use_default_shell_env = True.
  Replaces them using the POSIX toolchain provided by rules_sh.
• On Windows some tools are found in paths containing spaces, e.g. C:\Program Files\....
  This requires additional quoting in some places.

[mboes]

w00t! Depending on whether this or #1142 gets merged first, the comment in the CI setup for the bindist case should be updated accordingly.

[aherrmann]

Depending on whether this or #1142 gets merged first,

This PR transitively depends on #1142 through #1136

the comment in the CI setup for the bindist case should be updated accordingly.

Yes, I'll rebase and adapt the comment. Unfortunately, we cannot remove the flag, yet. @com_google_protobuf sets use_default_shell_env = True.

[mboes]

We should send them a PR to get them to use rules_sh. ;)

[aherrmann]

Turns out they're not using use_default_shell_env for PATH, but for LD_LIBRARY_PATH, so rules_sh won't help there. See protocolbuffers/protobuf#2933.

[mboes]

I opened protocolbuffers/protobuf#6886 to propose reverting protocolbuffers/protobuf#2933.

[aherrmann]

netlify got stuck. Force pushed to kick it.