[Python-3] UnicodeDecodeError when checking for an interpreter on Windows

[Don Olmstead]

[3/6] webkitpy.port.server_process_unittest.TestServerProcess.serial_test_basic erred:
  Traceback (most recent call last):
    File "C:\webkit\Tools\Scripts\webkitpy\port\server_process_unittest.py", line 114, in serial_test_basic
      proc.write(b'')
    File "C:\webkit\Tools\Scripts\webkitpy\port\server_process.py", line 183, in write
      self._start()
    File "C:\webkit\Tools\Scripts\webkitpy\port\server_process.py", line 134, in _start
      self._proc = self._target_host.executive.popen(self._cmd, stdin=self._target_host.executive.PIPE,
    File "C:\webkit\Tools\Scripts\webkitpy\common\system\executive.py", line 487, in popen
      line = f.readline()
    File "C:\Users\eolmstead\Documents\webkit-trunk\tools\python3\lib\encodings\cp1252.py", line 23, in decode
      return codecs.charmap_decode(input,self.errors,decoding_table)[0]
  UnicodeDecodeError: 'charmap' codec can't decode byte 0x90 in position 2: character maps to <undefined>

[Don Olmstead]

Created attachment 420690 [details]
Patch

[EWS]

Committed r273021: <https://commits.webkit.org/r273021>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 420690 [details].

[Radar WebKit Bug Importer]

<rdar://problem/74445592>