github(workflows): added "Build flatpak on new version tag" workflow

.github/workflows/dist_flatpak.yml

@@ -0,0 +1,67 @@
+name: Build flatpak on new version tag
+
+on:
+  push:
+    tags:
+      - "v*"
+
+permissions:
+  contents: write
+
+jobs:
+  flatpak:
+    name: "Build and release flatpak"
+    runs-on: ubuntu-latest
+    container:
+      image: ghcr.io/flathub-infra/flatpak-github-actions:gnome-48
+      options: --privileged
+    strategy:
+      matrix:
+        arch: [x86_64, aarch64]
+      # Don't fail the whole workflow if one architecture fails
+      fail-fast: false
+    steps:
+      - uses: actions/checkout@v5
+
+      - name: Install deps
+        if: ${{ matrix.arch != 'x86_64' }}
+        run: |
+          # Use the static binaries because it's unable to use a package manager 
+          curl https://download.docker.com/linux/static/stable/x86_64/docker-26.0.0.tgz --output ./docker.tgz
+          tar xzvf docker.tgz
+          mv docker/* /usr/bin
+      - name: Set up QEMU
+        if: ${{ matrix.arch != 'x86_64' }}
+        id: qemu
+        uses: docker/setup-qemu-action@v3
+        with:
+          platforms: arm64
+
+      - name: Set up JDK 17
+        uses: actions/setup-java@v4
+        with:
+          java-version: '17'
+          distribution: 'temurin'
+          cache: gradle
+
+      - name: Grant execute permission for gradlew
+        run: chmod +x gradlew
+      - name: Build appImage
+        run: ./gradlew packageAppImage
+
+      - name: Copy appImage
+        run: cp -r composeApp/build/compose/binaries/main/app/kitshn flatpak/source
+
+      - uses: flatpak/flatpak-github-actions/flatpak-builder@v6
+        with:
+          bundle: kitshn-${{ matrix.arch }}-${{ github.sha }}.flatpak
+          manifest-path: flatpak/app.kitshn.kitshn.yml
+          cache-key: flatpak-builder-${{ matrix.arch }}-${{ github.sha }}
+          arch: ${{ matrix.arch }}
+          upload-artifact: false
+
+      - name: Release artifacts
+        uses: softprops/action-gh-release@v2
+        if: github.ref_type == 'tag'
+        with:
+          files: kitshn-${{ matrix.arch }}-${{ github.sha }}.flatpak