Use linuxdeploy's bundled appimage plugin

As opposed to asking install-linuxdeploy to override it with an
upstream one.

.github/workflows/build.yaml

@@ -81,7 +81,7 @@ jobs:
       - name: Install linuxdeploy
         uses: pcolby/install-linuxdeploy@v1
         with:
-          plugins: appimage qt
+          plugins: qt
       - uses: actions/checkout@v4
       - name: Build
         id: build