feat: container build with automatical upload to ghcr

.github/workflows/container_build.yml

@@ -6,10 +6,16 @@ jobs:
   singularity-build:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - uses: eWaterCycle/setup-apptainer@v2
       with:
         apptainer-version: 1.3.0
 
     - name: Build Singularity container
-      run: apptainer build retinal-rl.sif resources/retinal-rl.def
+      run: apptainer build retinal-rl.sif resources/retinal-rl.def
+
+    - name: Scan classification config / ensure minimal functionality
+      run: singularity exec retinal-rl_singularity-image-latest.sif python main.py -m +experiment=cifar10-class-recon command=scan system.device=cpu
+
+    - name: Push to ghcr.io
+      run: singularity registry login --username ${{ github.actor }} --password ${{ secrets.GITHUB_TOKEN }} oras://ghcr.io; singularity push retinal-rl.sif oras://ghcr.io/berenslab/retinal-rl:singularity-image-latest