Release build workflow (#13616)

Along the way, factor out a chunk of the steps required to build the VSIX.

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

@@ -0,0 +1,34 @@
+name: 'Build VSIX'
+description: "Build the extension's VSIX"
+
+outputs:
+  path:
+    description: 'Path to the VSIX'
+    value: 'ms-python-insiders.vsix'
+
+runs:
+  using: 'composite'
+  steps:
+    # For faster/better builds of sdists.
+    - run: python -m pip install wheel
+      shell: bash
+
+    - run: python -m pip --disable-pip-version-check install -t ./pythonFiles/lib/python --no-cache-dir --implementation py --no-deps --upgrade -r requirements.txt
+      shell: bash
+
+    - run: |
+        python -m pip --disable-pip-version-check install -r build/debugger-install-requirements.txt
+        python ./pythonFiles/install_debugpy.py
+      shell: bash
+
+    - run: npm ci --prefer-offline
+      shell: bash
+
+    # Use the GITHUB_RUN_ID environment variable to update the build number.
+    # GITHUB_RUN_ID is a unique number for each run within a repository.
+    # This number does not change if you re-run the workflow run.
+    - run: npm run updateBuildNumber -- --buildNumber $GITHUB_RUN_ID
+      shell: bash
+
+    - run: npm run package
+      shell: bash

.github/workflows/insiders.yml

@@ -47,27 +47,12 @@ jobs:
       - name: Upgrade pip
         run: python -m pip install -U pip
 
-      - name: Install Python requirements
-        run: |
-          python -m pip --disable-pip-version-check install -t ./pythonFiles/lib/python --no-cache-dir --implementation py --no-deps --upgrade -r requirements.txt
-
-      - name: Install debugpy with wheels
-        run: |
-          python -m pip install wheel
-          python -m pip --disable-pip-version-check install -r build/debugger-install-requirements.txt
-          python ./pythonFiles/install_debugpy.py
-
-      - name: Install dependencies (npm ci)
-        run: npm ci --prefer-offline
-
-      # Use the GITHUB_RUN_ID environment variable to update the build number.
-      # GITHUB_RUN_ID is a unique number for each run within a repository.
-      # This number does not change if you re-run the workflow run.
-      - name: Update build number
-        run: npm run updateBuildNumber -- --buildNumber $GITHUB_RUN_ID
+      - name: Build VSIX
+        uses: ./.github/actions/build-vsix
+        id: build-vsix
 
-      - name: Create the VSIX
-        run: npm run package
+      - name: Rename VSIX
+        run: mv ${{ steps.build-vsix.outputs.path }} ${{ env.VSIX_NAME }}
 
       - uses: actions/upload-artifact@v2
         with: