Update appveyor.yml

appveyor.yml

@@ -6,7 +6,7 @@ environment:
     PYLSL_LIB: lsl.dll
   matrix:
     - ID: Ubuntu
-      APPVEYOR_BUILD_WORKER_IMAGE: Ubuntu2004
+      APPVEYOR_BUILD_WORKER_IMAGE: Ubuntu2104
       PY:  3.9
     - ID: macOS
       APPVEYOR_BUILD_WORKER_IMAGE: macOS
@@ -25,22 +25,7 @@ matrix:
   fast_finish: true
 
 install:
-  # Install Python 3.9 for max and linux
-  - sh: |
-      if [[ $APPVEYOR_BUILD_WORKER_IMAGE == "ubuntu" ]]; then
-          sudo add-apt-repository ppa:deadsnakes/ppa -y
-          sudo apt-get update
-          sudo apt-get install -y python3.9 python3.9-venv python3.9-dev python3-pip
-          python3.9 -m pip install --upgrade pip
-          which python3.9
-          sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.9 1
-          sudo update-alternatives --install /usr/bin/pip3 pip3 /usr/bin/pip3.9 1
-      elif [[ $APPVEYOR_BUILD_WORKER_IMAGE == "macOS" ]]; then
-          brew install [email protected]
-          ln -s /usr/local/opt/[email protected]/bin/python3.9 /usr/local/bin/python3
-          ln -s /usr/local/opt/[email protected]/bin/pip3.9 /usr/local/bin/pip3
-      fi
-      
+
   - sh: |
       if [[ $APPVEYOR_BUILD_WORKER_IMAGE == "ubuntu" ]]; then
           sudo apt-get update