b/a/noioutil: add an analyzer prohibiting use of ioutil

The ioutil package is deprecated and a tree-wide migration was already
done. This analyzer ensures that there can be no users of this package
in the future.

Change-Id: Ica6cd01ce5cb919d6f236225deeaff70b8e2800b
Reviewed-on: https://review.monogon.dev/c/monogon/+/451
Reviewed-by: Sergiusz Bazanski <serge@monogon.tech>
diff --git a/build/analysis/nogo_config.json b/build/analysis/nogo_config.json
index 8f97918..d2c824d 100644
--- a/build/analysis/nogo_config.json
+++ b/build/analysis/nogo_config.json
@@ -81,5 +81,10 @@
     "exclude_files": {
       "external/": "third_party"
     }
+  },
+  "noioutil": {
+    "exclude_files": {
+      "external/": "third_party"
+    }
   }
 }