link-checker: Remove broken URL to claim statement. (#8070)

This time for real, lets get link-checker green once again.

https://statement.polkadot.network/regular.html does not exist anymore.

Its really shitty that we are now only showing a multihash, but the url
is useless anyway. I also don't know what exactly was shown there.

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Co-authored-by: cmd[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: skunert

.config/lychee.toml

@@ -46,8 +46,12 @@ exclude = [
 	"https://w3f.github.io/parachain-implementers-guide/node/index.html",
 	"https://w3f.github.io/parachain-implementers-guide/protocol-chain-selection.html",
 	"https://w3f.github.io/parachain-implementers-guide/runtime/session_info.html",
+	# Genuinely broken, but exist as part of a signed statement. Rarely used, will be
+	# removed at some point.
+	"statement.polkadot.network",
 	# Behind a captcha (code 403):
 	"https://chainlist.org/chain/*",
+	"https://dl.acm.org",
 	"https://iohk.io/en/blog/posts/2023/11/03/partner-chains-are-coming-to-cardano/",
 	"https://polymesh.network",
 	"https://www.reddit.com/r/rust/comments/3spfh1/does_collect_allocate_more_than_once_while/",