where are we on qt6?

I am working on qgis 4.0.0 in wip, which can/should use qt6.  (qgis 3.44
and earlier use qt5.)   Things mostly work, and it's impressive to see
how much of qt6 is there.

(If you try wip/qgis, remember to make either a foo4.qgz copy or a
backup, because 4 will save the project with schema updated to 4, just
like any other qgis update.)

The only problem I have identified is that I get an error at startup
about the authentication system being missing.  This is about storing
secrets, e.g. database passwords.   nextcloud does this (with qt5), and
it seems this is done by

  qt5-qtkeychain-0.15.0nb2
  qt6-qtkeychain-0.15.0nb5
  
which are included by geography/qgis and wip/qgis.


in qgis 4's python console, I see (hand typed, cut/paste fails, grr)

  Authentication system is DISABLED:
  QCA's OpenSSL plugin (qca-ossl) is missing

I have in wip/qgis, carried forward, but commented out because I can't
find the package:

  #DEPENDS+= qca2-qt6-ossl-[0-9]*:../../security/qca2-qt6-ossl


Do people think that someone(tm) just needs to add qca2-qt6-foo for
various plugins, after adapting qca2-qt6 to be more amenable, with a
Makefile.common?

How is qca2-qt6 useful, with no providers?