Merge upstream 2.3.0 to main

[tvainika]

This skips or reverts most of our own local patches. Socks5 support
has landed upstream. Infinite loop related changes in aiven/main have
been fixed one way or another as per linking to submitted issues in
github. Only remaining changes are related to #32.

[tvainika]

These are the commits from aiven/main that were not from upstream:

The commit 719cf45 has been merged upstream as dpkp#2670

The commit dfe42d0 is from #32 which has not been submitted to dpkp/kafka-python yet.

The commit 4a1b2f3 is a fixup to a927ff2 see below

The commit c662d94 fixes KeyError. Not sure if submitted upstream ever, but dpkp/pull/2504 seems to be the fix for similar situation.

The commit 1a6bf01 and commit 919f61d are a change and its revert, not needed anymore.

The commit 4ca2f45 submitted upstream as dpkp#2189 to fix dpkp/issues/2188. Upstream merged alternative solution in dpkp/pull/2504

The commit 6985761 and commit a927ff2 are submitted upstream as dpkp#2194 to fix a bug dpkp#2193. Upstream has merged dpkp#2648 as alternative solution to the issue.

The commit 6efff52 is SOCKS5 support originally submitted as dpkp#2169 which upstream merged with rebase in dpkp#2531.

The commit ce7d853 was submitted upstream as dpkp/pull/2091. Upstream has merged dpkp/pull/2480 with notes that "CPU usage during broker outages should be improved" with that PR.