[core] Add Flatpak Files to Build Archive (#23)

Instead of downloading the Flatpak files from GitHub in the
"app.feeddeck.feeddeck.yml" file, we are now adding the files to the
archive we create during the release process.

app/linux/flatpak/app.feeddeck.feeddeck.yml

@@ -1,46 +0,0 @@
-app-id: app.feeddeck.feeddeck
-runtime: org.freedesktop.Platform
-runtime-version: "23.08"
-sdk: org.freedesktop.Sdk
-command: feeddeck
-
-finish-args:
-  - --share=ipc
-  - --socket=fallback-x11
-  - --socket=wayland
-  - --device=dri
-  - --share=network
-  - --filesystem=xdg-documents
-
-modules:
-  - name: FeedDeck
-    buildsystem: simple
-    build-commands:
-      - cp -R bundle /app/feeddeck
-      - mkdir -p /app/bin && ln -s /app/feeddeck/feeddeck /app/bin/feeddeck
-      - chmod +x /app/bin/feeddeck
-      - install -Dm644 app.feeddeck.feeddeck.svg /app/share/icons/hicolor/scalable/apps/app.feeddeck.feeddeck.svg
-      - install -Dm644 app.feeddeck.feeddeck.desktop -t /app/share/applications/
-      - install -Dm644 app.feeddeck.feeddeck.metainfo.xml -t /app/share/metainfo/
-    sources:
-      - type: file
-        url: https://raw.githubusercontent.com/feeddeck/feeddeck/main/app/linux/flatpak/app.feeddeck.feeddeck.desktop
-        sha256: c66ab88c9683b69914e12d4bc780a46473631b2539ca83503fae404145eae7cf
-      - type: file
-        url: https://raw.githubusercontent.com/feeddeck/feeddeck/main/app/linux/flatpak/app.feeddeck.feeddeck.metainfo.xml
-        sha256: 441fc4e08a6030b1e2238f93bced6e11f52da9d795d4a89c1609646609d61e16
-      - type: file
-        url: https://raw.githubusercontent.com/feeddeck/feeddeck/main/app/linux/flatpak/app.feeddeck.feeddeck.svg
-        sha256: 4a73d70cdaa6fe230eb802fe0f5456df46dfe399826b044086ad46b74c2bd6ce
-      - type: archive
-        only-arches:
-          - x86_64
-        url: https://github.com/feeddeck/feeddeck/releases/download/v1.0.0/feeddeck-linux-x86_64.tar.gz
-        sha256: f1dbdcb225cab2181ec7dec1606273fc72405dc64e11e4cded78843cdae9eda9
-        dest: bundle
-      - type: archive
-        only-arches:
-          - aarch64
-        url: https://github.com/feeddeck/feeddeck/releases/download/v1.0.0/feeddeck-linux-arm64.tar.gz
-        sha256: 7ef5d977b5ed16d22dc82e8b7dd0df72724b8f9fb2e31bbb88810b2a6a98724c
-        dest: bundle