Add keycloak build

.forgejo/workflows/build-keycloak.yaml

@@ -0,0 +1,21 @@
+on:
+  push:
+    paths:
+      - containers/keycloak/*
+      - .forgejo/workflows/build-keycloak.yaml
+jobs:
+  build-synapse:
+    runs-on: docker
+    container:
+      image: library/docker:dind
+    steps:
+      - run: apk add --no-cache nodejs git
+      - name: login to container registry
+        run: echo "${{ secrets.DEPLOY_TOKEN }}" | docker login --username ${{ secrets.DEPLOY_USER }} --password-stdin git.janky.solutions
+      - name: build container image
+        uses: docker/build-push-action@v4
+        with:
+          file: containers/keycloak/Containerfile
+          tags: git.janky.solutions/jankysolutions/infra/keycloak:latest
+          platforms: linux/amd64
+          push: true