Try improving the Pyodide Docker image caching

.github/workflows/gh-pages.yml

@@ -43,15 +43,15 @@ jobs:
         uses: ScribeMD/[email protected]
         with:
           key: docker-pyodide-${{ hashFiles('pyodide/Dockerfile') }}
-      - name: List all available Docker images
-        run: docker image ls
+      - name: Discover the cached Pyodide Docker image
+        run: echo "PYODIDE_DOCKER_IMAGE=$(docker images climet-eu/pyodide --format '{{.ID}}')" >> $GITHUB_ENV
       - name: Build the Pyodide Docker image
-        run: cd pyodide && docker build .
+        if: ${{ env.PYODIDE_DOCKER_IMAGE == '' }}
+        run: cd pyodide && docker build -t climet-eu/pyodide .
       - name: Build Pyodide and all required packages
         run: |
           cd pyodide
-          PYODIDE_DOCKER_IMAGE=$(docker build . -q) \
-            ./run_docker \
+          ./run_docker \
             --non-interactive \
             PYODIDE_PACKAGES="aiohttp,basemap,cdsapi,cfgrib,cf-units,cmcrameri,dask,earthkit,ecmwf-api-client,ecmwf-opendata,field-compression-benchmark,fsspec,git2,gribscan,h5netcdf,intake,ipyfilite,ipython,kerchunk,lzma,matplotlib,MetPy,netcdf4,numcodecs,numpy,pandas,pint,proplot,requests,scipy,sympy,s3fs,xarray,xeofs,zarr" \
             make