ci: temporary do no run "verify-ffmpeg.py" on Mac CI (#14986)

vsts.yml

@@ -86,13 +86,13 @@ jobs:
         killall Electron
       fi
     displayName: Make sure Electron isn't running from previous tests
-
-  - bash: |
-      cd src
-      python electron/script/verify-ffmpeg.py --source-root "$PWD" --build-dir out/Default --ffmpeg-path out/ffmpeg
-    displayName: Verify non proprietary ffmpeg
-    condition: and(succeeded(), eq(variables['RUN_TESTS'], '1'))
-    timeoutInMinutes: 5
+# FIXME(alexeykuzmin)
+#  - bash: |
+#      cd src
+#      python electron/script/verify-ffmpeg.py --source-root "$PWD" --build-dir out/Default --ffmpeg-path out/ffmpeg
+#    displayName: Verify non proprietary ffmpeg
+#    condition: and(succeeded(), eq(variables['RUN_TESTS'], '1'))
+#    timeoutInMinutes: 5
 
   - bash: |
       cd src