chore(CI): Use GNOME 49 image in CI action

Author: mfep

.github/workflows/ci.yml

@@ -26,7 +26,7 @@ jobs:
     name: Flatpak
     runs-on: ubuntu-latest
     container:
-      image: ghcr.io/flathub-infra/flatpak-github-actions:gnome-48
+      image: ghcr.io/flathub-infra/flatpak-github-actions:gnome-49
       options: --privileged
     steps:
     - uses: actions/checkout@v4