Address `click.utils.LazyFile` deprecation warning

[edgarrmondragon]

Starting with Click 8.5.0, LazyFile is deprecated and scheduled for removal in version 9:

• Mark clearly functions private status. Deprecated Python 2 utilities. pallets/click#3695

It's used in

check-jsonschema/src/check_jsonschema/cli/param_types.py

Lines 126 to 127 in d86c4c6

	class CustomLazyFile(click.utils.LazyFile):
	def __init__(

It's not urgent since this project constrains Click to <9, but re-implementing the functionality LazyFile might be rather easy.

[sirosen]

Yeah, I want to work on it a bit, but I haven't had time. I'm considering writing a library for handling several filesystem interactions (hashing, caching content, and lazy reads), which I have use for in other projects as well.

I'd be curious how easy a "quick fix" would be to maintain, if anyone wants to poke at it.

[edgarrmondragon]

I'd be curious how easy a "quick fix" would be to maintain

Vendoring _LazyFile is the quickest I can think of. It's ~90 lines and the implementation is not too hard to understand imo.