fix: update outdated typeof null bug reference to evergreen phrasing

Author: leonardomso

docs/concepts/equality-operators.mdx

@@ -12,7 +12,7 @@ console.log(1 == "1");   // true  — loose equality converts types
 console.log(1 === "1");  // false — strict equality checks type first
 
 // The famous quirks
-console.log(typeof null);  // "object" — a 28-year-old bug!
+console.log(typeof null);  // "object" — a bug from 1995!
 console.log(NaN === NaN);  // false — NaN never equals anything
 ```