Disable rust tests on Windows

The rust tests fail on Windows due to importing of exe_util which
imports pty which imports tty which imports termios (not present),
different handling of signals, and some slash/backslash mismatches just
for good measure. Fixing these tests is out-of-scope for this project so
I am disabling them on Windows to get "git cl presubmit --all" closer to
finishing without errors on Windows.

This change can most easily be tested with this command:

    git cl presubmit --files=testing/scripts/rust/*

Bug: 1309977
Change-Id: I94c4ef177f0304f05e5c753d481b38497bb56856
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3607149
Auto-Submit: Bruce Dawson <[email protected]>
Reviewed-by: Robert Sesek <[email protected]>
Commit-Queue: Robert Sesek <[email protected]>
Cr-Commit-Position: refs/heads/main@{#996151}
NOKEYCHECK=True
GitOrigin-RevId: 5dc44535691f8f0e923e654f987c8d38c817748e
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index f8dbf26..f6fcf97 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -8,6 +8,9 @@
 USE_PYTHON3 = True
 
 def CheckPythonUnittestsPass(input_api, output_api):
+    # The rust scripts and tests don't work on Windows.
+    if input_api.is_windows:
+        return []
     results = []
     this_dir = input_api.PresubmitLocalPath()