Exclude internetarchive's internal logging from Discord

[HebaruSan]

Problem

After #345, the archive.org-related Discord log spam is reduced to one of these every 5 minutes:

(MaxRetryError("HTTPSConnectionPool(host='s3.us.archive.org', port=443): Max retries exceeded with url: /?check_limit=1&accesskey=<KEY PRUNED> (Caused by ConnectTimeoutError(<urllib3.connection.HTTPSConnection object at 0x7fcb3cf37560>, 'Connection to s3.us.archive.org timed out. (connect timeout=12)'))"), 'https://s3.us.archive.org/?check_limit=1&accesskey=<KEY PRUNED>')

Cause

The Mirrorer is (appropriately) checking whether archive.org is overloaded here, which returns True:

NetKAN-Infra/netkan/netkan/mirrorer.py

Line 292 in 9831903

if self.ia_session.s3_is_overloaded(access_key=self.ia_access):

We don't log that message; internetarchive itself does, specifically here:

https://github.com/jjjake/internetarchive/blob/c578552d0c532f513b6e972b9f5529584b04c254/internetarchive/session.py#L539

This shouldn't be forwarded to Discord.

Changes

Now DiscordLogHandler's constructor accepts a regex to evaluate against each log record's logger name, which we pass as a zero-width negative lookahead assertion to exclude loggers containing internetarchive.