Fix Notebook Execution RuntimeError

Author: maryamziaa

.github/workflows/colab.yml

@@ -53,13 +53,10 @@ jobs:
         python -m pip install --progress-bar=off -e ./ml-agents-envs
         python -m pip install --progress-bar=off -e ./ml-agents
         python -m pip install --progress-bar=off -r colab_requirements.txt
-    -   name: Start Xvfb
-        run: |
-            sudo apt-get install xvfb
-            Xvfb :99 -screen 0 1024x768x16 &
-            export DISPLAY=:99
     - name: Execute notebook
-      run: jupyter nbconvert --to notebook --execute --log-level=DEBUG --ExecutePreprocessor.kernel_name=python3 --output output-${{ matrix.notebook_path }} colab/${{ matrix.notebook_path }}
+      run: |
+        python -m pip install asyncio
+        jupyter nbconvert --to notebook --execute --log-level=DEBUG --ExecutePreprocessor.kernel_name=python3 --output output-${{ matrix.notebook_path }} colab/${{ matrix.notebook_path }}
     - name: Upload colab results
       uses: actions/upload-artifact@v4
       with: