Bug 1776219 - Gracefully handle psutils failures in mach telemetry. r=firefox-build-system-reviewers,ahochheiden

On OpenBSD/i386, psutils fails in the generator used to enumerate the
active processes, breaking the build.

Differential Revision: https://phabricator.services.mozilla.com/D150462

python/mozbuild/mozbuild/telemetry.py

@@ -242,11 +242,6 @@ def get_vscode_running():
     """Return if the vscode is currently running."""
     try:
         import psutil
-    except Exception:
-        psutil = None
-
-    if not psutil:
-        return None
 
         for proc in psutil.process_iter():
             try:
@@ -262,5 +257,9 @@ def get_vscode_running():
             except Exception:
                 # may not be able to access process info for all processes
                 continue
+    except Exception:
+        # On some platforms, sometimes, the generator throws an
+        # exception preventing us to enumerate.
+        return False
 
     return False