ci: migrate from plugins/docker to woodpeckerci/plugin-docker-buildx

Replace the old Docker-in-Docker build approach (plugins/docker) with
the modern buildx plugin that natively supports BuildKit. This fixes:
- "Cannot connect to the Docker daemon" errors (no DinD needed)
- "the --mount option requires BuildKit" errors (buildx = BuildKit)
- OOM in publish step (skopeo no longer needed, buildx pushes directly)

Also removes the intermediate build-tag/skopeo-copy/publish dance —
buildx pushes both versioned and latest tags in a single step.

.woodpecker/api.yml

@@ -42,10 +42,11 @@ steps:
       - apt-get update && apt-get install -y --no-install-recommends libglib2.0-0
       - .venv/bin/pytest tests/integration/ tests/regression/ tests/e2e/ tests/test_listing_geojson.py -v --tb=short
 
-  - name: build-api-image
-    image: plugins/docker
-    environment:
-      DOCKER_BUILDKIT: 1
+  - name: build-and-push-api
+    image: woodpeckerci/plugin-docker-buildx
+    depends_on:
+      - test-unit
+      - test-integration
     settings:
       username: viktorbarzin
       password:
@@ -54,31 +55,16 @@ steps:
       dockerfile: Dockerfile
       context: .
       target: production
-      cache_from:
-        - viktorbarzin/realestatecrawler:latest
-        - viktorbarzin/realestatecrawler:builder
-      tags:
-        - "build-${CI_PIPELINE_NUMBER}"
-
-  - name: publish-api-image
-    image: alpine
-    depends_on:
-      - test-unit
-      - test-integration
-      - build-api-image
-    environment:
-      DOCKERHUB_TOKEN:
-        from_secret: dockerhub-token
-    commands:
-      - apk add --no-cache skopeo
-      - 'skopeo copy --src-creds "viktorbarzin:$DOCKERHUB_TOKEN" --dest-creds "viktorbarzin:$DOCKERHUB_TOKEN" "docker://docker.io/viktorbarzin/realestatecrawler:build-${CI_PIPELINE_NUMBER}" "docker://docker.io/viktorbarzin/realestatecrawler:${CI_PIPELINE_NUMBER}"'
-      - 'skopeo copy --src-creds "viktorbarzin:$DOCKERHUB_TOKEN" --dest-creds "viktorbarzin:$DOCKERHUB_TOKEN" "docker://docker.io/viktorbarzin/realestatecrawler:build-${CI_PIPELINE_NUMBER}" "docker://docker.io/viktorbarzin/realestatecrawler:latest"'
-      - 'skopeo copy --src-creds "viktorbarzin:$DOCKERHUB_TOKEN" --dest-creds "viktorbarzin:$DOCKERHUB_TOKEN" "docker://docker.io/viktorbarzin/realestatecrawler:build-${CI_PIPELINE_NUMBER}" "docker://docker.io/viktorbarzin/realestatecrawler:builder"'
+      platforms:
+        - linux/amd64
+      tag: ["${CI_PIPELINE_NUMBER}", "latest"]
+      cache_from: "viktorbarzin/realestatecrawler:latest"
+      cache_to: "type=inline"
 
   - name: update-deployment
     image: alpine
     depends_on:
-      - publish-api-image
+      - build-and-push-api
     commands:
       - apk add --no-cache curl jq
       - |

.woodpecker/frontend.yml

@@ -53,8 +53,13 @@ steps:
     commands:
       - cd frontend && npx vitest run --reporter=verbose --shard=4/4
 
-  - name: build-frontend-image
-    image: plugins/docker
+  - name: build-and-push-frontend
+    image: woodpeckerci/plugin-docker-buildx
+    depends_on:
+      - test-shard-1
+      - test-shard-2
+      - test-shard-3
+      - test-shard-4
     settings:
       username: viktorbarzin
       password:
@@ -63,31 +68,16 @@ steps:
       dockerfile: frontend/Dockerfile
       context: frontend
       target: production
-      cache_from:
-        - viktorbarzin/immoweb:latest
-      tags:
-        - "build-${CI_PIPELINE_NUMBER}"
-
-  - name: publish-frontend-image
-    image: alpine
-    depends_on:
-      - test-shard-1
-      - test-shard-2
-      - test-shard-3
-      - test-shard-4
-      - build-frontend-image
-    environment:
-      DOCKERHUB_TOKEN:
-        from_secret: dockerhub-token
-    commands:
-      - apk add --no-cache skopeo
-      - 'skopeo copy --src-creds "viktorbarzin:$DOCKERHUB_TOKEN" --dest-creds "viktorbarzin:$DOCKERHUB_TOKEN" "docker://docker.io/viktorbarzin/immoweb:build-${CI_PIPELINE_NUMBER}" "docker://docker.io/viktorbarzin/immoweb:${CI_PIPELINE_NUMBER}"'
-      - 'skopeo copy --src-creds "viktorbarzin:$DOCKERHUB_TOKEN" --dest-creds "viktorbarzin:$DOCKERHUB_TOKEN" "docker://docker.io/viktorbarzin/immoweb:build-${CI_PIPELINE_NUMBER}" "docker://docker.io/viktorbarzin/immoweb:latest"'
+      platforms:
+        - linux/amd64
+      tag: ["${CI_PIPELINE_NUMBER}", "latest"]
+      cache_from: "viktorbarzin/immoweb:latest"
+      cache_to: "type=inline"
 
   - name: update-deployment
     image: alpine
     depends_on:
-      - publish-frontend-image
+      - build-and-push-frontend
     commands:
       - apk add --no-cache curl jq
       - |