fix: remove custom inspect (#12262)

lib/associations/base.js

@@ -136,10 +136,6 @@ class Association {
   [Symbol.for('nodejs.util.inspect.custom')]() {
     return this.as;
   }
-
-  inspect() {
-    return this.as;
-  }
 }
 
 module.exports = Association;

lib/model.js

@@ -3230,10 +3230,6 @@ class Model {
     return this.name;
   }
 
-  static inspect() {
-    return this.name;
-  }
-
   static hasAlias(alias) {
     return Object.prototype.hasOwnProperty.call(this.associations, alias);
   }