feat: Add S390x support (kserve#138)

#### Modifications
Added linux/s390x ( platform ) in the build github workflow 

#### Result

https://github.com/modassarrana89/modelmesh/actions/runs/8688245342/job/23823937204
// Build operation run in local workflow is a success. Attached archieve
log for refernece

[logs_22763759557.zip](https://github.com/kserve/modelmesh/files/14978607/logs_22763759557.zip)

---------

Signed-off-by: Modassar Rana <[email protected]>

Author: modassarrana89

.github/workflows/build.yml

@@ -78,12 +78,10 @@ jobs:
 
           # print env vars for debugging
           cat "$GITHUB_ENV"
-
       - name: Build and push runtime image
         uses: docker/build-push-action@v4
         with:
-          # for linux/s390x, maven errors due to missing io.grpc:protoc-gen-grpc-java:exe:linux-s390_64:1.51.1
-          platforms: linux/amd64,linux/arm64/v8,linux/ppc64le
+          platforms: linux/amd64,linux/arm64/v8,linux/ppc64le,linux/s390x
           target: runtime
           push: ${{ github.event_name == 'push' }}
           tags: ${{ env.IMAGE_NAME }}:${{ env.VERSION }}