build: fix ffmpeg generation on Windows non-x64 (#47768)

* build: fix ffmpeg generation on Windows non-x64

* test: ffmpeg artifact

.github/actions/build-electron/action.yml

@@ -38,6 +38,12 @@ runs:
       run: |
         GN_APPENDED_ARGS="$GN_EXTRA_ARGS target_cpu=\"x64\" v8_snapshot_toolchain=\"//build/toolchain/mac:clang_x64\""
         echo "GN_EXTRA_ARGS=$GN_APPENDED_ARGS" >> $GITHUB_ENV
+    - name: Set GN_EXTRA_ARGS for Windows
+      shell: bash
+      if: ${{inputs.target-arch != 'x64' && inputs.target-platform == 'win' }}
+      run: |
+        GN_APPENDED_ARGS="$GN_EXTRA_ARGS target_cpu=\"${{ inputs.target-arch }}\""
+        echo "GN_EXTRA_ARGS=$GN_APPENDED_ARGS" >> $GITHUB_ENV
     - name: Add Clang problem matcher
       shell: bash
       run: echo "::add-matcher::src/electron/.github/problem-matchers/clang.json"
@@ -184,8 +190,8 @@ runs:
           electron/script/zip-symbols.py -b $BUILD_PATH
         fi
     - name: Generate FFMpeg ${{ inputs.step-suffix }}
-      shell: bash
       if: ${{ inputs.is-release == 'true' }}
+      shell: bash
       run: |
         cd src
         gn gen out/ffmpeg --args="import(\"//electron/build/args/ffmpeg.gn\") use_remoteexec=true $GN_EXTRA_ARGS"