docs: typo fix Update cairo_precompiles.md

[mdqst]

Description

I noticed a small grammatical issue in the documentation regarding the Cairo precompiles section. The sentence:

"The selector of the Cairo function being called should always be present in the contract called."

was a bit awkward and not quite in line with proper English syntax. It should read:

"The selector of the Cairo function being called should always be present in the called contract."

The change was made to correct the word order and ensure clarity.

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

[Eikix]

Sorry for the late reply and lack of review. We've been pausing the development of kakarot for now.

I'm cognizant that you spent some time doing this PR, so thank you. I will have to close it since I am cleaning a bit the repo and preparing for archival.

Archiving the repo will solve issue of people working on stuff while we are not accepting new PRs.
Thanks for understanding