Fix Building of Static Binaries With Go 1.20

Explicitly disable CGO when building binaries.  As of Go 1.20, we get
dynamic executables when using standard libary packages that have both
cgo and pure Go implementations.

Fixes errors in which release binaries may fail because the correct
version of libc can't be linked at runtime.

See golang/go#58550

Makefile

@@ -18,16 +18,16 @@ install-debug:
 	go install ${LDFLAGS} ${GCFLAGS}
 
 $(WINDOWS):
-	env GOOS=windows GOARCH=amd64 go build -v -o $(WINDOWS) ${LDFLAGS}
+	env CGO_ENABLED=0 GOOS=windows GOARCH=amd64 go build -v -o $(WINDOWS) ${LDFLAGS}
 
 $(LINUX):
-	env GOOS=linux GOARCH=amd64 go build -v -o $(LINUX) ${LDFLAGS}
+	env CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -v -o $(LINUX) ${LDFLAGS}
 
 $(OSX_AMD64):
-	env GOOS=darwin GOARCH=amd64 go build -v -o $(OSX_AMD64) ${LDFLAGS}
+	env CGO_ENABLED=0 GOOS=darwin GOARCH=amd64 go build -v -o $(OSX_AMD64) ${LDFLAGS}
 
 $(OSX_ARM64):
-	env GOOS=darwin GOARCH=arm64 go build -v -o $(OSX_ARM64) ${LDFLAGS}
+	env CGO_ENABLED=0 GOOS=darwin GOARCH=arm64 go build -v -o $(OSX_ARM64) ${LDFLAGS}
 
 $(basename $(WINDOWS)).zip: $(WINDOWS)
 	zip $@ $<