Merge pull request #2120 from dprotaso/use-go-1-20

use go1.20

Author: k8s-ci-robot

docker/Dockerfile.webhook

@@ -13,7 +13,7 @@
 # limitations under the License.
 
 ARG BUILDPLATFORM=linux/amd64
-FROM --platform=$BUILDPLATFORM golang:1.19 AS build-env
+FROM --platform=$BUILDPLATFORM golang:1.20 AS build-env
 RUN mkdir -p /go/src/sig.k8s.io/gateway-api
 WORKDIR /go/src/sig.k8s.io/gateway-api
 COPY  . .