rules: remove unused rule-category meta

scripts/lint.py

@@ -801,15 +801,12 @@ def lint_rule(ctx: Context, rule: Rule):
         # this is by far the most common reason to be in the nursery,
         # and ends up just producing a lot of noise.
         if not (is_nursery_rule(rule) and len(violations) == 1 and violations[0].name == "missing examples"):
-            category = rule.meta.get("rule-category")
-
             print("")
             print(
-                "%s%s %s"
+                "%s%s"
                 % (
                     "    (nursery) " if is_nursery_rule(rule) else "",
                     rule.name,
-                    ("(%s)" % category) if category else "",
                 )
             )