Downgrade Firefox version to fix failing robot-framework tests (azimuth-cloud#211)

Author: sd109

.github/actions/test/action.yml

@@ -30,6 +30,28 @@ runs:
         source ./bin/activate "$AZIMUTH_CONFIG_ENVIRONMENT" "$AZIMUTH_ENVIRONMENT"
         ansible-playbook azimuth_cloud.azimuth_ops.generate_tests -e @extra-vars.yml
 
+    - name: Downgrade installed firefox browser version
+      shell: bash
+      # Based on https://support.mozilla.org/en-US/kb/install-firefox-linux
+      run: |
+        set -e
+        # Import Mozilla repo key
+        sudo install -d -m 0755 /etc/apt/keyrings
+        wget -q https://packages.mozilla.org/apt/repo-signing-key.gpg -O- | sudo tee /etc/apt/keyrings/packages.mozilla.org.asc > /dev/null
+        # Check fingerprint
+        if [[ $(gpg -n -q --import --import-options import-show /etc/apt/keyrings/packages.mozilla.org.asc | grep 35BAA0B33E9EB396F59CA838C0BA5CE6DC6315A3) ]]; then
+          echo "Fingerprint matches"
+        else
+          echo "Mozilla repo fingerprint doesn't match expected"
+          exit 1
+        fi
+        # Add repo to sources
+        echo "deb [signed-by=/etc/apt/keyrings/packages.mozilla.org.asc] https://packages.mozilla.org/apt mozilla main" | sudo tee -a /etc/apt/sources.list.d/mozilla.list > /dev/null
+        # Install Firefox extended support release
+        sudo apt update
+        sudo apt remove firefox # Uninstall default version (1.136.0)
+        sudo apt install -y firefox-esr # Install older version (1.128)
+
     - name: Run test suite
       shell: bash
       run: |