ci: Use Windows VM initialized via script (#21882)

* ci: use VM initialized via setup script

* update depot_tools location

* Handle bad src archive files

* Use proper version of windbg

appveyor.yml

@@ -29,7 +29,7 @@
 
 version: 1.0.{build}
 build_cloud: libcc-20
-image: vs2019-16.3-10.0.18362
+image: vs2019bt-16.4.0
 environment:
   GIT_CACHE_PATH: C:\Users\electron\libcc_cache
   ELECTRON_OUT_DIR: Default
@@ -88,8 +88,17 @@ build_script:
         if (Test-Path -Path $zipfile) {
           # file exists, unzip and then gclient sync
           7z x -y $zipfile -mmt=30 -aoa
-          # update external binaries
-          python src/electron/script/update-external-binaries.py
+          if (-not (Test-Path -Path "src\buildtools")) {
+            # the zip file must be corrupt - resync
+            $env:RUN_GCLIENT_SYNC="true"
+            if ($env:TARGET_ARCH -ne 'ia32') {
+              # only save on x64/woa to avoid contention saving
+              $env:SAVE_GCLIENT_SRC="true"
+            }
+          } else {
+            # update external binaries
+            python src/electron/script/update-external-binaries.py
+          }
         } else {    
           # file does not exist, gclient sync, then zip
           $env:RUN_GCLIENT_SYNC="true"
@@ -122,7 +131,7 @@ build_script:
   - gn check out/Default //electron:manifests
   - gn check out/Default //electron/shell/common/api:mojo
   - if DEFINED RAW_GOMA_AUTH (ninja -j 300 -C out/Default electron:electron_app) else (ninja -C out/Default electron:electron_app)
-  - if "%GN_CONFIG%"=="testing" ( python C:\Users\electron\depot_tools\post_build_ninja_summary.py -C out\Default )
+  - if "%GN_CONFIG%"=="testing" ( python C:\depot_tools\post_build_ninja_summary.py -C out\Default )
   - gn gen out/ffmpeg "--args=import(\"//electron/build/args/ffmpeg.gn\") %GN_EXTRA_ARGS%"
   - ninja -C out/ffmpeg electron:electron_ffmpeg_zip
   - ninja -C out/Default electron:electron_dist_zip