Duplicated `APPROVE` macro in the ERC20 contract

[iFrostizz]

This is a good find from sashik.eth, so reposting here for tracking purposes, and it's a "good first issue" for anyone who wanna take it.

"
Why in huffmate/ERC20 "approve" macro declared twice?
https://github.com/huff-language/huffmate/blob/main/src/tokens/ERC20.huff#L98
https://github.com/huff-language/huffmate/blob/main/src/tokens/ERC20.huff#L248
"

By the way, one message later, he mentioned that huff-rs should not allow this to compile. So the current huffmate ERC20 is broken

"
Previous versions of huff allowed to compile this? because with the current I receive:
Error: Duplicate MACRO name found: \"APPROVE\" \nMACRO names should be unique
"

[MathisGD]

Fixed by #134 already