unable to update CLI tools to the latest version on macOS

**firebase-tools:** 9.3.0

**Platform:** macOS

I follow steps from the documentation to update CLI tools https://firebase.google.com/docs/cli#macos

```
% curl -sL https://firebase.tools | upgrade=true bash
-- Checking for existing firebase-tools on PATH...
Your machine already has firebase-tools@9.3.0 installed. Nothing to do.
-- All done!
```

I expect the CLI tools should be updated to the latest version, but it says "Nothing to do" instead.

Start with the macOS CLI update instructions at https://firebase.google.com/docs/cli#macos and reproduce the reported command: curl -sL https://firebase.tools | upgrade=true bash. Trace how the installer detects the existing firebase-tools@9.3.0 and decides that there is nothing to do. Done means the documented command updates an older installation to the latest CLI version.

Written by the indexing model from the issue text.