Please don’t do that. Either the question is on topic and valid, in which case it should remain for others to benefit from, or else it’s off-topic and shouldn’t be here, and posting and then deleting once you’ve gotten what you’ve wanted is abusing the system.
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
The safest way is to include the whole license file anywhere you want, and refer to the permissions granted by it in your license (which can be MIT, GPL etc.).
The MIT license simply says “has to be included” so as long as you include the license text anywhere, you won’t even need to mention it.
Also, maybe you don’t even need to put the React source code in your repo! Just use package.json. In that case, you don’t need to include the license for your dependencies because you are not redistributing React, just referring to it in package.json.
If you create (distribute) some downloadable release containing a node_modules folder or JS files, then if you use npm or some CDN with a <script> tag, those distributions of React will also contain the necessary license text that should be sufficient for you.
Look at this - even minified JS releases of React contain necessary license information.