Build with Go v1.21

Longhorn 7341

Signed-off-by: Eric Weber <eric.weber@suse.com>

Dockerfile.dapper

@@ -33,7 +33,7 @@ RUN if [ ${ARCH} == "s390x" ]; then \
 # Install Go & tools
 ENV GOLANG_ARCH_amd64=amd64 GOLANG_ARCH_arm64=arm64 GOLANG_ARCH_s390x=s390x GOLANG_ARCH=GOLANG_ARCH_${ARCH} \
     GOPATH=/go PATH=/go/bin:/usr/local/go/bin:${PATH} SHELL=/bin/bash
-RUN wget -O - https://storage.googleapis.com/golang/go1.20.3.linux-${!GOLANG_ARCH}.tar.gz | tar -xzf - -C /usr/local && \
+RUN wget -O - https://storage.googleapis.com/golang/go1.21.3.linux-${!GOLANG_ARCH}.tar.gz | tar -xzf - -C /usr/local && \
     go install golang.org/x/lint/golint@latest
 
 VOLUME /tmp