text: Title: tox does not work on my Windows environment due to char-code incorrespondence
  Body: ## Issue
  
  tox does not work due to try to read with invalid encoding (try to read "UTF-8" but actual encoding is "sjis")
  
  ```
    py39: commands succeeded
    lint: commands succeeded
  ERROR:   strictlint: undefined
  Traceback (most recent call last):
    File "C:\Users\username\AppData\Local\Programs\Python\Python39\lib\runpy.py", line 197, in _run_module_as_main
      return _run_code(code, main_globals, None,
    File "C:\Users\username\AppData\Local\Programs\Python\Python39\lib\runpy.py", line 87, in _run_code
      exec(code, run_globals)
    File "C:\repopath\.venv\Scripts\tox.exe\__main__.py", line 7, in <module>
    File "C:\repopath\.venv\lib\site-packages\tox\session\__init__.py", line 44, in cmdline
      main(args)
    File "C:\repopath\.venv\lib\site-packages\tox\session\__init__.py", line 69, in main
      exit_code = session.runcommand()
    File "C:\repopath\.venv\lib\site-packages\tox\session\__init__.py", line 197, in runcommand
      return self.subcommand_test()
    File "C:\repopath\.venv\lib\site-packages\tox\session\__init__.py", line 225, in subcommand_test
      run_sequential(self.config, self.venv_dict)
    File "C:\repopath\.venv\lib\site-packages\tox\session\commands\run\sequential.py", line 9, in run_sequential
      if venv.setupenv():
    File "C:\repopath\.venv\lib\site-packages\tox\venv.py", line 649, in setupenv
      status = self.update(action=action)
    File "C:\repopath\.venv\lib\site-packages\tox\venv.py", line 282, in update
      self.hook.tox_testenv_install_deps(action=action, venv=self)
    File "C:\repopath\.venv\lib\site-packages\pluggy\_hooks.py", line 265, in __call__
      return self._hookexec(self.name, self.get_hookimpls(), kwargs, firstresult)
    File "C:\repopath\.venv\lib\site-packages\pluggy\_manager.py", line 80, in _hookexec
      return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
    File "C:\repopath\.venv\lib\site-packages\pluggy\_callers.py", line 60, in _multicall
      return outcome.get_result()
    File "C:\repopath\.venv\lib\site-packages\pluggy\_result.py", line 60, in get_result
      raise ex[1].with_traceback(ex[2])
    File "C:\repopath\.venv\lib\site-packages\pluggy\_callers.py", line 39, in _multicall
      res = hook_impl.function(*args)
    File "C:\repopath\.venv\lib\site-packages\tox\venv.py", line 803, in tox_testenv_install_deps
      venv._install(deps, action=action)
    File "C:\repopath\.venv\lib\site-packages\tox\venv.py", line 495, in _install
      self.run_install_command(packages=packages, options=options, action=action)
    File "C:\repopath\.venv\lib\site-packages\tox\venv.py", line 437, in run_install_command
      self._pcall(
    File "C:\repopath\.venv\lib\site-packages\tox\venv.py", line 618, in _pcall
      return action.popen(
    File "C:\repopath\.venv\lib\site-packages\tox\action.py", line 132, in popen
      lines = out_path.read_text("UTF-8").split("\n")
    File "C:\repopath\.venv\lib\site-packages\py\_path\common.py", line 171, in read_text
      return f.read()
    File "C:\Users\username\AppData\Local\Programs\Python\Python39\lib\codecs.py", line 322, in decode
      (result, consumed) = self._buffer_decode(data, self.errors, final)
  UnicodeDecodeError: 'utf-8' codec can't decode byte 0x83 in position 10466: invalid start byte
  ```
  
  It worked correctly anyway by change char code literal in the above stacktrace
  ```python
  lines = out_path.read_text("UTF-8").split("\n")
  ```
  
  as sjis
  
  ```python
  lines = out_path.read_text("sjis").split("\n")
  ```
  
  Is there any way to specify the literal charcode, or any way to the files be UTF-8 (what files?)?
  
  
  
  ## Environment
  
  Provide at least:
  
  - OS: Windows 10
  
  <details open>
  <summary>Output of <code>pip list</code> of the host Python, where <code>tox</code> is installed</summary>
  
  ```console
  
  ```
  
  </details>
  
  ## Output of running tox
  
  <details open>
  <summary>Output of <code>tox -rvv</code></summary>
  
  ```console
  
  ```
  
  </details>
  
  ## Minimal example
  
  <!--  If possible, provide a minimal reproducer for the issue. -->
  
  ```console
  
  ```
  