Use vendor prefix for versions if not using go mod

scripts/build

@@ -8,13 +8,17 @@ PKG="github.com/rancher/k3s"
 PKG_CONTAINERD="github.com/containerd/containerd"
 PKG_RANCHER_CONTAINERD="github.com/rancher/containerd"
 PKG_CRICTL="github.com/kubernetes-sigs/cri-tools"
+VENDOR_PREFIX=
+if [ -z "$(go mod why 2>/dev/null)" ]; then
+    VENDOR_PREFIX="${PKG}/vendor/"
+fi
 
 VERSIONFLAGS="
-    -X $PKG/pkg/version.Version=$VERSION
-    -X $PKG/pkg/version.GitCommit=${COMMIT:0:8}
-    -X $PKG_CONTAINERD/version.Version=$VERSION_CONTAINERD
-    -X $PKG_CONTAINERD/version.Package=$PKG_RANCHER_CONTAINERD
-    -X $PKG_CRICTL/pkg/version.Version=$VERSION_CRICTL"
+    -X ${PKG}/pkg/version.Version=${VERSION}
+    -X ${PKG}/pkg/version.GitCommit=${COMMIT:0:8}
+    -X ${VENDOR_PREFIX}${PKG_CONTAINERD}/version.Version=${VERSION_CONTAINERD}
+    -X ${VENDOR_PREFIX}${PKG_CONTAINERD}/version.Package=${PKG_RANCHER_CONTAINERD}
+    -X ${VENDOR_PREFIX}${PKG_CRICTL}/pkg/version.Version=${VERSION_CRICTL}"
 LDFLAGS="
     -w -s"
 STATIC="