fix: ordering of dev and post components

[JeanChristopheMorinPerso]

Description

This PR fixes a small bug with dev and post components in versions that I found while working on adding version interval ranges support to rattler.

Basically, I found that rattler was considering a version 1.2devdev to be smaller than 1.2dev. This I think is wrong based on https://github.com/conda/ceps/blob/main/cep-0033.md and conda.models.version.VersionOrder agrees with that.

The same problem also happened with the post component, but in reverse.

>>> import rattler
>>> rattler.Version('1.2dev') < rattler.Version('1.2devdev')
False
>>> rattler.Version('1.2post') > rattler.Version('1.2postpost')
False

while in conda:

>>> conda.models.version.VersionOrder('1.2dev') < conda.models.version.VersionOrder('1.2devdev')
True
>>> conda.models.version.VersionOrder('1.2post') > conda.models.version.VersionOrder('1.2postpost')
True

The problem seem to stem from the fact that tag_no_case kind of matched on the prefix, I think. I'm still very new to rust, so I might be wrong. But the fix seems legit to me.

The docs on tag_no_case say (emphasis mine):

will return the part of the input that matches the argument with no regard to case.

(https://docs.rs/nom/latest/nom/bytes/fn.tag_no_case.html)

How Has This Been Tested?

AI Disclosure

• This PR contains AI-generated content.
  • I have tested any AI-generated content in my PR.
  • I take responsibility for any AI-generated content in my PR.

Tools: Amp (see https://ampcode.com/threads/T-019d36ed-fd10-7368-b400-481c3646f900, in this case it used gpt 5.4 in its deepest thinking mode)

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added sufficient tests to cover my changes.

[baszalmstra]

I think we also have checks to see if something is a dev version? Maybe we can assert those too here?