Prefer charset_normalizer for char detection

[nijel]

charset_normalizer is a dependency for requests, while chardet is not, so it is more likely to be found.

For vendored requests this would still load whatever is available.

The reason I noticed this memory profiling in case both libraries are present and charset_normalizer has way lower memory footprint than chardet.

[sigmavirus24]

Just don't install chardet

[nijel]

I'd love to, but it's a dependency for a third-party library (otsaloma/gaupol#222).

What is actually the reason for trying chardet first when it's not dependency for requests? It's just an extra import that is very likely to fail.