Update 'preflight.sh' (#899)

As per title to support Go 1.18

Co-authored-by: Phil S <ullarah@noreply@mills.io>
Reviewed-on: #899
Reviewed-by: James Mills <james@mills.io>
Co-authored-by: Phil S. <ullarah@noreply@mills.io>
Co-committed-by: Phil S. <ullarah@noreply@mills.io>

preflight.sh

@@ -75,8 +75,8 @@ check_goversion() {
 
   gover="$(go version | grep -o -E 'go[0-9]+\.[0-9]+(\.[0-9]+)?')"
 
-  if ! go version | grep -E 'go1\.17(\.[0-9]+)?' > /dev/null; then
-    log2 "Go 1.17 is required, found ${gover}"
+  if ! go version | grep -E 'go1\.1[678](\.[0-9]+)?' > /dev/null; then
+    log2 "Go 1.16+ is required, found ${gover}"
     return 1
   fi