Add experimental Debian package autobuild

.gitea/workflows/release.yml

@@ -1,5 +1,7 @@
 ---
 on:
+  push:
+    branches: [deb-auto/exp]
   release:
     types: [published]
 jobs:
@@ -23,5 +25,37 @@ jobs:
           target/release/gt-tool-${{ github.ref_name }}-$(arch)
         env:
           RELEASE_KEY_GITEA: ${{ secrets.RELEASE_KEY_GITEA }}
+  debian-release:
+    name: Build and upload the Debian 12 package
+    runs-on: ubuntu-latest
+    container:
+      image: debian:12
+    steps:
+      - name: Install Tools
+        run: >
+          apt-get update;
+          apt-get install -y --no-install-recommends
+            build-essential
+            git
+            git-buildpackage;
+      - name: Checkout Repo (can't use actions/checkout@v4, no NodeJS)
+        run: git clone ${{ github.event.repository.clone_url }}
+      - name: Switch to Debian package branch
+        run: git checkout deb
+      - name: Install build-deps
+        run: apt-get build-dep .
+        working-directory: /root/gt-tool
+      - name: Build the package
+        run: gbp buildpackage
+      - name: Install the tool we just built
+        run: dpkg -i gt-tool*.deb # TODO: Pick out the exact version instead of globbing
+      - name: Upload the packaging parts
+        run: > # The file globs are like that to avoid matching the gt-tool/ folder. I don't want that uploaded.
+          gt-tool
+          -u ${{ vars.DEST_GITEA }} -r ${{ vars.DEST_REPO }}
+          upload-release
+          "${{ github.ref_name }}"
+          gt-tool-*
+          gt-tool_*
 ...