chore: replace deprecated jest.autoRun in .vscode/settings.json (v…

…ercel#66609)

### Why?

![Screenshot 2024-06-07 at 2 22
00 AM](https://github.com/vercel/next.js/assets/120007119/61334227-afac-4221-ade7-0b0bb653cee0)

Since `jest.autoRun` in `.vscode/settings.json` is deprecated, this PR
replaces it with an equivalent setting using the recommended migration
guide.

> Starting from v6.1.0, if no runMode is defined in settings.json, the
extension will automatically generate one using legacy settings
(autoRun, showCoverageOnLoad). To migrate, simply use the "Jest: Save
Current RunMode" command from the command palette to update the setting,
then remove the deprecated settings.

x-ref:
https://github.com/jest-community/vscode-jest/blob/master/README.md#autorun

.vscode/settings.json

@@ -16,8 +16,9 @@
     "typescript",
     "typescriptreact"
   ],
-  // Disable Jest autoRun as otherwise it will start running all tests the first time.
-  "jest.autoRun": "off",
+  // Set Jest runMode to on-demand as otherwise it will start running all tests the first time.
+  // Equivalent to deprecated option "jest.autoRun": "off"
+  "jest.runMode": "on-demand",
   // Debugging.
   "debug.javascript.unmapMissingSources": true,
   "files.exclude": {