Harden Flatpak workflow permissions and version handling

Agent-Logs-Url: https://github.com/f4exb/sdrangel/sessions/862cd268-1d4c-402d-b530-b2885bf6d153

Co-authored-by: srcejon <57259258+srcejon@users.noreply.github.com>

.github/workflows/flatpak.yml

@@ -8,6 +8,9 @@ on:
       - 'v*'
   workflow_dispatch:
 
+permissions:
+  contents: write
+
 jobs:
   build_flatpak:
     runs-on: ubuntu-latest
@@ -22,15 +25,8 @@ jobs:
           if [[ "${{ github.ref_name }}" == "flatpak" ]]; then
             echo "version=${{ github.sha }}" >> "$GITHUB_OUTPUT"
           else
-            echo "version=$(echo "${{ github.ref_name }}" | cut -c2-)" >> "$GITHUB_OUTPUT"
+            echo "version=${{ github.ref_name#v }}" >> "$GITHUB_OUTPUT"
           fi
-      - name: Install dependencies
-        run: |
-          sudo apt-get update
-          sudo apt-get install -y flatpak flatpak-builder
-      - name: Add Flathub remote
-        run: |
-          flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
       - name: Build Flatpak
         uses: flatpak/flatpak-github-actions/flatpak-builder@v6
         with: