feat(W-24078824): add legacy deprecation message

README.md

@@ -1,5 +1,8 @@
 # @oclif/plugin-legacy
 
+⚠️ **This library has been deprecated.** ⚠️
+oclif no longer supports the use of legacy plugins.
+
 converts older style plugins to be compatible with oclif
 
 [![Version](https://img.shields.io/npm/v/@oclif/plugin-legacy.svg)](https://npmjs.org/package/@oclif/plugin-legacy)

eslint-suppressions.json

@@ -9,11 +9,6 @@
       "count": 1
     }
   },
-  "eslint.config.mjs": {
-    "n/no-unsupported-features/node-builtins": {
-      "count": 3
-    }
-  },
   "src/index.ts": {
     "@eslint-community/eslint-comments/require-description": {
       "count": 1