ci(toolchains): remove second docker-cache artifact write

Newer action versions complain about the name being the same. There is
not much to cache in the second run, regardless.

Author: thewtex

.github/workflows/toolchains.yml

@@ -70,20 +70,9 @@ jobs:
         if [[ -e ./docker-cache/itk-wasm-emscripten-base.tar.xz ]]; then xz -d -k < ./docker-cache/itk-wasm-emscripten-base.tar.xz | docker load ; fi
         if [[ -e ./docker-cache/itk-wasm-emscripten.tar.xz ]]; then xz -d -k < ./docker-cache/itk-wasm-emscripten.tar.xz | docker load ; fi
         ./src/docker/itk-wasm/build.sh
-        mkdir -p ./docker-cache
-        docker save itkwasm/emscripten:latest | xz -e9 -T0 > ./docker-cache/itk-wasm-emscripten.tar.xz
 
     - name: Build itk-wasi
       run: |
         if [[ -e ./docker-cache/itk-wasm-wasi-base.tar.xz ]]; then xz -d -k < ./docker-cache/itk-wasm-wasi-base.tar.xz | docker load ; fi
         if [[ -e ./docker-cache/itk-wasm-wasi.tar.xz ]]; then xz -d -k < ./docker-cache/itk-wasm-wasi.tar.xz | docker load ; fi
         ./src/docker/itk-wasm/build.sh --with-wasi
-        mkdir -p ./docker-cache
-        docker save itkwasm/wasi:latest | xz -e9 -T0 > ./docker-cache/itk-wasm-wasi.tar.xz
-
-    - name: Cache docker results
-      uses: actions/upload-artifact@v4
-      with:
-        name: docker-cache
-        path: ./docker-cache
-        retention-days: 7