[release-0.10] - Adds dependency on github.com/grafana/jsonnet-libs mixins-util (#2480)

* Add lockfile

* chore: ignore mdox errors for https://www.weave.works

* ci: Generate with newer go version

jsonnetfile.lock.json

@@ -41,6 +41,16 @@
       "version": "02db06f540086fa3f67d487bd01e1b314853fb8f",
       "sum": "B49EzIY2WZsFxNMJcgRxE/gcZ9ltnS8pkOOV6Q5qioc="
     },
+    {
+      "source": {
+        "git": {
+          "remote": "https://github.com/grafana/jsonnet-libs.git",
+          "subdir": "mixin-utils"
+        }
+      },
+      "version": "d9ba581fb27aa6689e911f288d4df06948eb8aad",
+      "sum": "LoYq5QxJmUXEtqkEG8CFUBLBhhzDDaNANHc7Gz36ZdM="
+    },
     {
       "source": {
         "git": {