Update CI to use Harmonic

Signed-off-by: Rhys Mainwaring <[email protected]>

.github/workflows/ubuntu-build.yml

@@ -51,12 +51,12 @@ jobs:
           python3-vcstool \
           python3-colcon-common-extensions
 
-      - name: Install Gazebo Garden
+      - name: Install Gazebo Harmonic
         run: |
           sudo wget https://packages.osrfoundation.org/gazebo.gpg -O /usr/share/keyrings/pkgs-osrf-archive-keyring.gpg
           echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/pkgs-osrf-archive-keyring.gpg] http://packages.osrfoundation.org/gazebo/ubuntu-stable $(lsb_release -cs) main" | sudo tee /etc/apt/sources.list.d/gazebo-stable.list > /dev/null
           sudo apt update && sudo apt install --no-install-recommends -y \
-          gz-garden
+          gz-harmonic
 
       - name: Build
         run: |