revert previous changes to lychee file

Author: krofax

lychee.toml

@@ -27,9 +27,6 @@ exclude_loopback = true
 # Exclude all mail addresses from checking.
 exclude_mail = true
 
-# Exclude all external links except ethereum-optimism GitHub
-exclude_links = ['http[s]?://(?!github\.com/ethereum-optimism).*']
-
 # Exclude RPC URLs from checking.
 exclude = [
     'https://mainnet.optimism.io',