fix(deps) update kube-state-metrics source repo branch to main (#1968)

* update ksm target git branch name

* `jb update`; `make generate`

jsonnet/kube-prometheus/jsonnetfile.json

@@ -64,7 +64,7 @@
           "subdir": "jsonnet/kube-state-metrics"
         }
       },
-      "version": "master"
+      "version": "main"
     },
     {
       "source": {
@@ -73,7 +73,7 @@
           "subdir": "jsonnet/kube-state-metrics-mixin"
         }
       },
-      "version": "master"
+      "version": "main"
     },
     {
       "source": {