plasma-pa: fix audio test

When pressing the 'Test' button from the Settings application,
plasma-pa will call libcanberra to play a sample sound.

Without libcanberra-pulse installed, the test will fail with "No
driver" since libcanberra cannot find any plugins.

Make sure at least the alsa and pulse plugins are installed so that
the test succeeds.

I can now hear a nice bing!

Note: I think only libcanberra-pulse is needed but I added both just
to be sure.

Signed-off-by: Marc Ferland <marc.ferland@sonatest.com>

recipes-plasma/plasma-pa.inc

@@ -31,6 +31,11 @@ DEPENDS += " \
     libcanberra \
 "
 
+RDEPENDS:${PN} += " \
+    libcanberra-alsa \
+    libcanberra-pulse \
+"
+
 inherit cmake_plasma
 inherit kf6-kdoctools