Update upgrading and deployment docs
Copy the 0.12.1 release notes into main branch
Document need for Nginx `proxy_set_header Host` config [trac#5612]

This avoids issues with incorrect URLs in RSS feeds.
Use newer celery `shared_task` API to support celery > 4.3
Mention Elisei for the bcrypt fix
Add Bill to AUTHORS
Update documentation URLs

These documented URLs previously returned a 302 redirect to a 404 page.
Revert removal of install-sh due to CI build failures

This reverts commit 2b20fff967e8fa94ca20f499fd13e07e0b7cb2c6.
build intermediate files are going into .gitignore
Document how to refer to a remote database (srht#30)
a7b3d867 — Olivier Mehani 2 months ago
Fix remaining bcrypt issue
Remove Fedora 36 build until we support Python 3.10

SourceHut only supports back to Fedora 36, so we can't still run our Fedora 33
build anyway.
Revert test change
Remove Fedora 36 build until we have Python 3.10 support
Drop Debian 10 support
Upgrade to latest pip
Remove unneeded pin for zipp now we have a more recent pip
Specify a minimum pip 20.2.4
Switch from `setup.py develop` to `pip install --editable .`

It's no longer recommended to use setup.py directly. This also potentially gives
us access to recent version of Pip that have better dependency resolution.
Remove unused pyconfigure M4 macros

Turns out we weren't using these at all.