deps: update JUnitProgressIndicator for Python 3

Update the revert we're floating to add back the JUnit output for
the V8 test runner for Python 3.

Author: richardlau

deps/v8/tools/testrunner/testproc/progress.py

@@ -365,7 +365,7 @@ def __init__(self, junitout, junittestsuite):
 
     self.outputter = junit_output.JUnitTestOutput(junittestsuite)
     if junitout:
-      self.outfile = open(junitout, "w")
+      self.outfile = open(junitout, "wb")
     else:
       self.outfile = sys.stdout