Revert "build,docker: add support for riscv64"

This reverts commit 765cffe6c2.

.github/workflows/docker-image.yml

@@ -107,31 +107,18 @@ jobs:
           cache-from: type=local,src=/tmp/.buildx-cache
           cache-to: type=local,dest=/tmp/.buildx-cache-new
 
-      - name: Build Docker image (linux/riscv64)
-        uses: docker/build-push-action@v4
-        with:
-          platforms: linux/riscv64
-          context: .
-          push: false
-          load: true
-          file: ./Dockerfile
-          tags: ${{ env.IMAGE_NAME }}:linux-riscv64
-          cache-from: type=local,src=/tmp/.buildx-cache
-          cache-to: type=local,dest=/tmp/.buildx-cache-new
-
       # We test all the images on amd64 host here. This uses QEMU to emulate
       # the other platforms.
       - run: docker run --rm $IMAGE_NAME:linux-amd64 --version
       - run: docker run --rm $IMAGE_NAME:linux-arm-v7 --version
       - run: docker run --rm $IMAGE_NAME:linux-arm64-v8 --version
-      - run: docker run --rm $IMAGE_NAME:linux-riscv64 --version
 
       # This will only push the previously built images.
       - if: github.event_name != 'workflow_dispatch' || github.event.inputs.push == 'true'
         name: Publish to Docker Hub
         uses: docker/build-push-action@v4
         with:
-          platforms: linux/amd64,linux/arm/v7,linux/arm64/v8,linux/riscv64
+          platforms: linux/amd64,linux/arm/v7,linux/arm64/v8
           context: .
           push: true
           file: ./Dockerfile

mk/util.mk

@@ -16,7 +16,6 @@ SUPPORTED_PLATFORMS += linux-arm
 SUPPORTED_PLATFORMS += linux-arm64
 SUPPORTED_PLATFORMS += linux-386
 SUPPORTED_PLATFORMS += linux-amd64
-SUPPORTED_PLATFORMS += linux-riscv64
 
 SUPPORTED_PLATFORMS += darwin-amd64
 ifeq ($(shell bin/check_go_version "1.16.0" 2>/dev/null; echo $$?),0)