Remove GitHub Cache support for now (future release or buildkit cache provider?)

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

.github/workflows/ci.yml

@@ -107,35 +107,3 @@ jobs:
         name: Dump context
         if: always()
         uses: crazy-max/ghaction-dump-context@v1
-
-  github-cache:
-    runs-on: ubuntu-latest
-    steps:
-      -
-        name: Checkout
-        uses: actions/checkout@v2.3.1
-      -
-        name: Set up QEMU
-        uses: ./setup-qemu/ # change to docker/setup-qemu-action@master
-        with:
-          platforms: all
-      -
-        name: Set up Docker Buildx
-        id: buildx
-        uses: ./setup-buildx/ # change to docker/setup-buildx-action@master
-      -
-        name: Build with cache
-        uses: ./
-        with:
-          context: ./test
-          file: ./test/Dockerfile-multi-golang
-          builder: ${{ steps.buildx.outputs.name }}
-          platforms: linux/amd64,linux/arm64
-          cache-github: true
-          tags: |
-            localhost:5000/name/app:latest
-            localhost:5000/name/app:1.0.0
-      -
-        name: Dump context
-        if: always()
-        uses: crazy-max/ghaction-dump-context@v1