Spontaneous file upload max_files not working as expected

[jbcallaghan]

Bug:
Spontaneous file upload doesn't fully honour the max_files setting. (Chainlit 1.3.2)

Reproduce:

config.toml
[features.spontaneous_file_upload]
enabled = true
accept = ["/"]
max_files = 1
max_size_mb = 10

1. Click to attach a file
2. Select one file and click open
3. Now click attach a file again
4. Select another file and click open

And now you have exceeded the max_files restriction.

Expected:

You should be prevented from attaching further files when the limit set in config.toml has been reached.