fix: files_transfer benchmark (#3944)

tooling/bench/tests/files_transfer/public/index.html

@@ -15,7 +15,7 @@
           .invoke('tauri', {
             __tauriModule: 'Fs',
             message: {
-              cmd: 'readBinaryFile',
+              cmd: 'readFile',
               path: '.tauri_3mb.json',
               options: {
                 // home folder

tooling/bench/tests/files_transfer/src-tauri/tauri.conf.json

@@ -35,7 +35,8 @@
     "allowlist": {
       "all": false,
       "fs": {
-        "readFile": true
+        "readFile": true,
+        "scope": ["$HOME/.tauri_3mb.json"]
       }
     },
     "windows": [