Makefile: set -buildvcs=false

see: ko-build/ko#672

It changed in go1.18 and is breaking CI for others too.

Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>

Makefile

@@ -4,7 +4,7 @@ NUMCPUS=`grep -c '^processor' /proc/cpuinfo`
 GUEST_IPV4_ADDR = 192.168.20.1/24
 
 gokvm: $(wildcard *.go) $(wildcard */*.go)
-	go build .
+	go build -buildvcs=false .
 
 golangci-lint:
 	curl --retry 5 -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh \