Here’s what actually fixed it:

Run npm config set legacy-peer-deps false in the terminal.

Delete node_modules and package-lock.json.

In some cases, you may also need to delete functions the firebase and set it up again.

Run firebase deploy --only functions.

Finally, don’t forget to run npm install inside the functions folder before deploying again.

See the reference where I discovered this: https://stackoverflow.com/a/77823349/23242867