Update github actions to work with new builds

e2e:
- Enable buildx.
- Build only for linux/amd64 and export the built image.

Signed-off-by: Sunny <darkowlzz@protonmail.com>

.github/workflows/e2e.yaml

@@ -12,6 +12,15 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v2
+      - name: Setup QEMU
+        uses: docker/setup-qemu-action@v1
+        with:
+          platforms: all
+      - name: Setup Docker Buildx
+        id: buildx
+        uses: docker/setup-buildx-action@v1
+        with:
+          buildkitd-flags: "--debug"
       - name: Restore Go cache
         uses: actions/cache@v1
         with:
@@ -44,7 +53,7 @@ jobs:
             exit 1
           fi
       - name: Build container image
-        run: make docker-build IMG=test/kustomize-controller:latest
+        run: make docker-build IMG=test/kustomize-controller:latest BUILD_PLATFORMS=linux/amd64 BUILD_ARGS=--load
       - name: Load test image
         run: kind load docker-image test/kustomize-controller:latest
       - name: Install CRDs