OpenBSD ftp is down, let us switch to CDN

It happens from time to time while switching between branches and/or
updating after someone else's changes that regtests are run by accident
on the wrong binary, typically the one the tests were run on during
development and not with the latest adaptations. And obviously it's
when this happens that we break the CI. There are various causes to
this but they all come down to humans context-switching a lot, and
there's no real fix for this that doesn't add even more burden hence
increases the overhead. However we can help the human detect such
mistakes very easily.

This change here will compare the version of the haproxy binary to
the version of the tree, and will emit a warning in the regtest output
if they do not match, regardless of the outcome of the test. This is
sufficient in case of failures because these are quickly glanced over,
and is sufficient as well in case of accidental success because the
warning is the last message. E.g:

  ########################## Starting vtest ##########################
  Testing with haproxy version: 2.7-dev10-cfcdbc-38
  Warning: version does not match the current tree (2.7-dev10-111c78-39)
  0 tests failed, 0 tests skipped, 182 tests passed

This should not affect builds made out of a git tree because the version
is retrieved using "make version", or exactly the same way as it's passd
to the haproxy binary. We just need to know what "make" command to run,
so $MAKE is used primarily, falling back to "make" then to "gmake". In
case all of these fail, we just ignore the version check. This should be
sufficient to catch human mistakes without affecting the CI.

Since Marko announced at HAProxyConf 2022 that the data plane API is
mostly complete and will now follow the same release cycle as haproxy
starting with 2.7, it's probably the right moment to encourage users
to start trying it so that we can hope to migrate all the painful
discovery stuff there in a not too distant future.

Let's just point to the latest release for now. We'll see in the future
if we need to adapt the link depending on the branch.

This is 32nd iteration of typo fixes

during CI builds QuicTLS is not cached, let us speed it up by
disabling tests build. Doing so saves ~40s out of 3m40.

Some components like Discourse were already redirecting to https. Other
ones like docs and git are covered by the certificate, and finally
switching the advertised scheme for www should increase the ratio of
H2 and H3 in the stats (resp 8.9 and 1.9%) and possibly help spot new
issues.

 this allows to pass QUICTLS_EXTRA_ARGS to QUICTLS builds. if no
 additional arg is passed, behaviour is kept unchanged

--
v2 indentation fixed

Now when publishing a release, if make-releases-json is usable at the same
place, it will be called to regenerate the json index of available versions.

This will be used to rebuild a releases.json file in each download
directory. It only relies on existing files and sorts them by version,
appends known signatures (md5/sha256) and marks the most recent one as
the latest release.

This aims at addressing github issue #1537.

This is the shortened URL of the nightly builds maintained by William,
let's have them in announce messages.