+1 maintainance

[Dimitri John Ledkov]

finishing off boost1.71 transition
boost1.67 -> boost1.71 was started last cycle, but there were a few
packages still using boost1.67 in focal. Notably those that were still
using boost-python2. Uploaded: regina-normal uwsgi libpwiz ompl
freeorion mongo-cxx-driver-legacy frogatto innoextract. This completes
transition to boost1.71 and drops boost-python2, such that only
boost-python3 is now available.

Normally I look at oldest packages stuck in update-excuses. Not sure
what happened to the "days" counter, because I am sure some of them
have been stuck for multiple cycles now. Some of them are now more
urgent as they ftbfs and are holding up transition to libgcc-s1.

unanimity
stuck forever, FTBFS, removed from Debian
Opened an RM bug report to drop it from groovy-proposed. When and if,
it is fixed in Debian, it will be synced over again. Until them AA
should remove it. Also added update-excuse tag on the bug, such that
update-excuses documents this triange.
https://bugs.launchpad.net/ubuntu/+source/unanimity/+bug/1882059

ubuntu-app-launch url-dispatcher and the three indicators
Unity8 is removed from the archive. Three indicators have codepaths
for Unity8 DE. They use url-dispatcher. Which uses ubuntu-app-launch.
Which FTBFS in groovy due to glib depreceations and unity.h headers
doing weird redefines on glib macros which now fail. Drop those code
paths from indicators, to ensure we can kick
ubuntu-app-launch/url-dispatcher from the archive. If and when,
something equivalent is re-introduced in the archive, and it all
builds from source, these codepaths can be reintroduced back in. (e.g.
if there is lomiri-app-launch at one point).

singularity-container
Try to improve buildability, document next steps in a bug report
tagged ftbfs & update-excuse

fftw3
Cheat, fixup the fixup of the autopkgtest fixup to stop building fftw3
mpi based packages on i386. This should reduce the scope of packages
built on i386 significantly.

uwsgi-plugin-luajit
I think built against old uwsgi, retried the build record
uwsgi-plugin-php
forcesync to get it to build
... and uwsgi & friends should migrate now

boost1.67 transition done, it can now be removed from Ubuntu.

--
Regards,

Dimitri.