storage: remove usage of secret placeholder

src/storage/interface.js

@@ -40,13 +40,13 @@ const assert = require('node:assert'),
     BoxError = require('../boxerror.js');
 
 function removePrivateFields(apiConfig) {
-    // in-place removal of tokens and api keys with constants.SECRET_PLACEHOLDER
+    // in-place removal of tokens and api keys
     return apiConfig;
 }
 
 // eslint-disable-next-line no-unused-vars
 function injectPrivateFields(newConfig, currentConfig) {
-    // in-place injection of tokens and api keys which came in with constants.SECRET_PLACEHOLDER
+    // in-place injection of tokens and api keys
 }
 
 async function getAvailableSize(apiConfig) {