Refactor sprites build

[FallenDeity]

Change description

Cloning all of the sprites submodule just to build this repo is redundant since all we do is just check paths the actual sprite data is never used, hence this pr now uses the manifest published whenever there is a change in sprites repo to build the sprites introduced in pr PokeAPI/sprites#289

a manifest is published both as raw json and gzipped json in compressed format for example view here https://pokeapi.github.io/sprites/manifest.json its published both via releases and github pages which is used as a catalogue to build all the data for sprites in build.py

AI coding assistance disclosure

None

Contributor check list

• I have written a description of the contribution and explained its motivation.
• I have written tests for my code changes (if applicable).
• I have read and understood the AI Assisted Contribution guidelines.
• I will own this change in production, and I am prepared to fix any bugs caused by my code change.