Confirm adding ppa for audio waveform

Now displays a message that needs to be confirmed.

Author: tf

.github/workflows/tests.yml

@@ -117,7 +117,7 @@ jobs:
     - name: Install audiowaveform package
       if: ${{ matrix.install-audiowaveform == true}}
       run: |
-        sudo add-apt-repository ppa:chris-needham/ppa
+        sudo add-apt-repository -y ppa:chris-needham/ppa
         sudo apt-get update
         sudo apt-get install audiowaveform