Remove outdated code (#13996)

src/language-js/print/property.js

@@ -23,11 +23,6 @@ function printPropertyKey(path, options, print) {
   const parent = path.getParentNode();
   const { key } = node;
 
-  // flow has `Identifier` key, other parsers use `PrivateIdentifier` (ESTree) or `PrivateName`
-  if (node.type === "ClassPrivateProperty" && key.type === "Identifier") {
-    return ["#", print("key")];
-  }
-
   if (options.quoteProps === "consistent" && !needsQuoteProps.has(parent)) {
     const objectHasStringProp = (
       parent.properties ||