Don't run cipd from depot_tools, it lives in a different location on Swarming.

Bug: b/264453023
Change-Id: I3a149c0a70b11a1718a73afcda6644a4d3b3c93f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/4138059
Auto-Submit: Brian Ryner <bryner@google.com>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>

cros

@@ -80,7 +80,7 @@ def _CheckPythonVersion():
 
 def _BootstrapVpython27():
   """Installs the vpython2.7 packages into the cipd cache directory."""
-  subprocess.run([DEPOT_TOOLS_DIR / 'cipd', 'ensure',
+  subprocess.run(['cipd', 'ensure',
                   '-log-level', 'info',
                   '-ensure-file',
                   DEPOT_TOOLS_DIR / 'cipd_manifest_cros_python2.txt',