CSV dialect sniffer gets wrong dialect (excel) when tab delimited csv file has long header fields

# Bug report

### Bug description:

CSV dialect sniffer gets wrong dialect (excel) when tab delimited csv file has long header fields.

This issue is lifted up here as it was initially raised in the `jc` cli github repo. Here:

https://github.com/kellyjonbrazil/jc/issues/465

### CPython versions tested on:

3.10

### Operating systems tested on:

Linux