flatpak: Build recent libadwaita version

With updated CSS we use some variables intoduced in stable versions of libadwaita. To make it work properly, stop using alpha.2 and build recent stable version.

pkgs/flatpak/com.github.rafostar.Clapper.json

@@ -34,7 +34,7 @@
         "flathub/lib/uchardet.json",
         "flathub/gstreamer-1.0/gstreamer.json",
         "testing/gtk4.json",
-        "flathub/lib/libadwaita.json",
+        "testing/libadwaita.json",
         "testing/gtuber.json",
         {
             "name": "clapper",

pkgs/flatpak/testing/libadwaita.json

@@ -0,0 +1,21 @@
+{
+    "name": "libadwaita",
+    "buildsystem": "meson",
+    "config-opts": [
+        "--buildtype=release",
+        "--wrap-mode=nofallback",
+        "-Dintrospection=enabled",
+        "-Dvapi=false",
+        "-Dgtk_doc=false",
+        "-Dtests=false",
+        "-Dexamples=false"
+    ],
+    "sources": [
+        {
+            "type": "git",
+            "url": "https://gitlab.gnome.org/GNOME/libadwaita.git",
+            "tag": "1.1.1",
+            "commit": "5ec9f624b23bf78b29dd708e77ccdfcee0a9867a"
+        }
+    ]
+}