Add Flatpak platform version

Author: ben221199

.github/workflows/flatpak-beta.yml

@@ -17,7 +17,7 @@ jobs:
       - name: Setup Flatpak
         run: |
           flatpak remote-add --if-not-exists --user flathub https://flathub.org/repo/flathub.flatpakrepo
-          flatpak install flathub org.freedesktop.Platform org.freedesktop.Sdk -y
+          flatpak install flathub org.freedesktop.Platform//25.08 org.freedesktop.Sdk -y
       - name: Build Flatpak
         run: flatpak-builder --repo=repo --force-clean build-dir org.lbry.cli.json
       - name: Build Bundle