:electron: Add flathub store publish pipeline (#6307)

* add tokens to replace in release pipeline for metainfo release dates/versions

* validate the metainfo in pipeline

* install appstream first

* release notes in the metainfo

* release notes for metainfo - testing pipeline

* pipeline works

* brand colors as per flathub recommendation

* picked colours following flathubs recommendations

* contrast

* contrast checked

* updating nightly flow to also work with new metainfo for testing

* replacing manifest info and creating pr

* minor improvements

* release notes

* upgrade action

.github/workflows/electron-pr.yml

@@ -34,6 +34,7 @@ jobs:
           source .venv/bin/activate
           python3 -m pip install setuptools
       - if: ${{ startsWith(matrix.os, 'ubuntu') }}
+        name: Setup Flatpak dependencies
         run: |
           sudo apt-get update
           sudo apt-get install flatpak -y
@@ -42,6 +43,14 @@ jobs:
           sudo flatpak install org.freedesktop.Sdk//24.08 -y
           sudo flatpak install org.freedesktop.Platform//24.08 -y
           sudo flatpak install org.electronjs.Electron2.BaseApp//24.08 -y
+
+          METAINFO_FILE="packages/desktop-electron/extra-resources/linux/com.actualbudget.actual.metainfo.xml"
+          TODAY=$(date +%Y-%m-%d)
+          VERSION=$(node ./packages/ci-actions/bin/get-next-package-version.js --package-json ./packages/desktop-electron/package.json --type nightly)
+          sed -i "s/%RELEASE_VERSION%/$VERSION/g; s/%RELEASE_DATE%/$TODAY/g" "$METAINFO_FILE"
+          sudo apt-get install appstream
+          appstreamcli --version
+          appstreamcli validate "$METAINFO_FILE"
       - name: Set up environment
         uses: ./.github/actions/setup
       - name: Build Electron