Split ros2 docker images into 2 jobs for easier maintenance

.github/workflows/docker.yml

@@ -6,7 +6,60 @@ on:
       - 'master'
 
 jobs:
+  docker_deps:
+    runs-on: ubuntu-latest
+    
+    strategy:
+      matrix:
+        docker_tag: [focal-foxy-deps, humble-deps]
+        include:
+        - docker_tag: focal-foxy-deps
+          docker_tags: |
+            introlab3it/rtabmap:focal-foxy-deps
+          docker_platforms: |
+            linux/amd64
+            linux/arm64
+          docker_path: 'focal-foxy/deps'
+        - docker_tag: humble-deps
+          docker_tags: |
+            introlab3it/rtabmap:humble-deps
+          docker_platforms: |
+            linux/amd64
+            linux/arm64
+          docker_path: 'humble/deps'
+    
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v2
+      - 
+        name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+        with:
+          platforms: all
+      -
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+      -
+        name: Login to DockerHub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+      -
+        name: Build and push
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          push: true
+          platforms: ${{ matrix.docker_platforms }}
+          file: ./docker/${{ matrix.docker_path }}/Dockerfile
+          tags: ${{ matrix.docker_tags }}
+          cache-from: type=registry,ref=introlab3it/rtabmap:${{ matrix.docker_tag }}
+          cache-to: type=inline
+  
   docker:
+    needs: docker_deps
     runs-on: ubuntu-latest
     
     strategy: