Add Gitea Actions workflow to build and push Docker image

Builds the deb Dockerfile and pushes to Gitea container registry.
Requires REGISTRY_USER and REGISTRY_PASSWORD secrets.

.gitea/workflows/build-and-push.yml

@@ -0,0 +1,43 @@
+name: Build and Push Docker Image
+
+on:
+  push:
+    branches: [master]
+  workflow_dispatch:
+
+env:
+  REGISTRY: git.johnogle.info
+  IMAGE_NAME: johno/protonmail-bridge-docker
+
+jobs:
+  build-deb:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to Gitea Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ secrets.REGISTRY_USER }}
+          password: ${{ secrets.REGISTRY_PASSWORD }}
+
+      - name: Get bridge version
+        id: version
+        run: |
+          VERSION=$(cat deb/PACKAGE | grep -oP '\d+\.\d+\.\d+' | head -1 || echo "latest")
+          echo "version=${VERSION}" >> $GITHUB_OUTPUT
+
+      - name: Build and push (deb)
+        uses: docker/build-push-action@v5
+        with:
+          context: ./deb
+          push: true
+          tags: |
+            ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest
+            ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ steps.version.outputs.version }}
+          platforms: linux/amd64