🏃‍♂️ pass git state to build from makefile

Signed-off-by: Ashish Amarnath <ashisham@vmware.com>

hack/build.sh

@@ -39,10 +39,13 @@ if [ -z "${VERSION}" ]; then
     exit 1
 fi
 
+if [ -z "${GIT_SHA}" ]; then
+    echo "GIT_SHA must be set"
+    exit 1
+fi
+
 export CGO_ENABLED=0
 
-GIT_SHA=$(git rev-parse HEAD)
-GIT_DIRTY=$(git status --porcelain 2> /dev/null)
 if [[ -z "${GIT_DIRTY}" ]]; then
   GIT_TREE_STATE=clean
 else