ci: use system python to download external binaries (#21234)

* ci: use system python to download external binaries on MacOS

* ci: manually download external binaries for all OS

.circleci/config.yml

@@ -160,6 +160,9 @@ step-gclient-sync: &step-gclient-sync
         "$CIRCLE_REPOSITORY_URL"
 
       gclient sync --with_branch_heads --with_tags
+      
+      # Manually run update-external-binaries.py with system python
+      python src/electron/script/update-external-binaries.py
 
 step-setup-env-for-build: &step-setup-env-for-build
   run:

DEPS

@@ -49,7 +49,7 @@ vars = {
 
   # It is always needed for normal Electron builds,
   # but might be impossible for custom in-house builds.
-  'download_external_binaries': True,
+  'download_external_binaries': False,
 
   'checkout_nacl':
     False,

appveyor.yml

@@ -53,6 +53,8 @@ build_script:
       %GCLIENT_EXTRA_ARGS%
       "https://github.com/electron/electron"
   - gclient sync --with_branch_heads --with_tags --reset
+  # Manually run update-external-binaries.py with system python
+  - python src/electron/script/update-external-binaries.py
   - cd src
   - ps: $env:BUILD_CONFIG_PATH="//electron/build/args/%GN_CONFIG%.gn"
   - gn gen out/Default "--args=import(\"%BUILD_CONFIG_PATH%\") %GN_EXTRA_ARGS%"