🌱 bump dockerfile to use Go 1.20

Dockerfile

@@ -1,4 +1,4 @@
-# syntax=docker/dockerfile:1.1-experimental
+# syntax=docker/dockerfile:1
 
 # Copyright 2020 The Kubernetes Authors.
 #
@@ -15,7 +15,7 @@
 # limitations under the License.
 
 # Build the manager binary
-ARG GOVER=1.19.7
+ARG GOVER=1.20.10
 FROM golang:${GOVER} as builder
 
 WORKDIR /workspace

hack/boilerplate/boilerplate.Dockerfile.txt

@@ -1,4 +1,4 @@
-# syntax=docker/dockerfile:1.1-experimental
+# syntax=docker/dockerfile:1
 
 # Copyright YEAR The Kubernetes Authors.
 #
@@ -12,4 +12,4 @@
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
-# limitations under the License.
+# limitations under the License.