Update GitHub Actions workflows. (#562)

This PR was automatically generated by the
update-workflows-ecosystem-providers workflow in the pulumi/ci-mgmt
repo, from commit 2490813024dfe37d27606bd4d9845b5584abe174.

Author: pulumi-bot

.github/workflows/run-acceptance-tests.yml

@@ -125,14 +125,17 @@ jobs:
         tools: pulumictl, pulumicli, ${{ matrix.language }}
     - name: Download bin
       uses: ./.github/actions/download-bin
-    - run: dotnet nuget add source ${{ github.workspace }}/nuget
+    - name: Add NuGet source
+      if: matrix.language == 'dotnet'
+      run: dotnet nuget add source ${{ github.workspace }}/nuget
     - name: Download SDK
       uses: ./.github/actions/download-sdk
       with:
         language: ${{ matrix.language }}
     - name: Update path
       run: echo "${{ github.workspace }}/bin" >> "$GITHUB_PATH"
     - name: Install Python deps
+      if: matrix.language == 'python'
       run: |-
         pip3 install virtualenv==20.0.23
         pip3 install pipenv