setup: avoid setuptools 67 - it can't handle celery's broken pytz dependency

With setuptools 67 or later, launching Kallithea fails as:

$ gearbox serve -c my.ini --reload
15:56:54,111 ERROR [gearbox] Expected closing RIGHT_PARENTHESIS
pytz (>dev)
~^

The `packaging` vendored in setuptools cannot handle the broken syntax
`Requires-Dist: pytz (>dev)` in
venv/lib/python3.11/site-packages/celery-5.0.5.dist-info/METADATA .

The old celery version currently used by Kallithea is wrong, and setuptools has
moved on after a reasonable grace period. We thus have to work around and avoid
latest setuptools.

See https://github.com/pypa/setuptools/issues/3889 .

gearbox: replace paster with something TurboGears2-ish that still works with the Pylons stack

This is a step towards moving away from the Pylons stack to TurboGears2, but
still independent of it.


Some notes from the porting - it could perhaps be the missing(?) documentation
for migrating from paster to gearbox:

Note: 'gearbox' without parameters will crash - specify '-h' to get started
testing.

Replace paster
summary = 'yada yada'
with the first line of the docstring of the Command class ... or override
get_description.

Note: All newlines in the docstring will be collapsed and mangle the long help
text.

Grouping of commands is not possible. Standard commands (for development) can't
be customized under the same name or hidden. (Like for paster, the conceptual
model also assumes that the sub-command naming is namespaced so commands from
other packages won't conflict.)

The usage help is fully automated from the declared options.

For all deprecated Commands, replace paster
hidden = True
with gearbox
deprecated = True

Note: config_file, takes_config_file, min_args and max_args are not available /
relevant.

The gearbox parser is customized by overriding get_parser - there is nothing
like paster update_parser.

Gearbox is using argparse instead of optparse ... but argparse add_argument is
mostly backwards compatible with optparse add_option.

Instead of overriding command or run as in paster, override take_action in
gearbox. The parsed arguments are passed to take_action, not available on the
command instance.

Paster BadCommand is not available and must be handled manually, terminating
with sys.exit(1).

There is no standard make-config command in gearbox.

Paster appinstall has been replaced by the somewhat different setup_app module
in gearbox. There is still no clean way to pass parameters to SetupAppCommand
and it relies on websetup and other apparently unnecessary complexity. Instead,
implement setup-db from scratch.


Minor change by Thomas De Schampheleire: add gearbox logging configuration.
Because we use logging.config.fileConfig(.inifile) during gearbox command
execution, the logging settings need to be correct and contain a block for
gearbox logging itself. Otherwise, errors in command processing are not even
visible and the command exits silently.

Turbogears2 migration: use sqlalchemy.url iso sqlalchemy.db1.url

In Turbogears2, much of the application initialization is handled by the
framework, whereas in Pylons the application was responsible for it.
Initializing SQLAlchemy is one such part of initialization which is handled
by Turbogears2.

Turbogears2 expects the configuration file to refer to the database using
'sqlalchemy.url' rather than the current 'sqlalchemy.db1.url'. While the
exact name is not really important, not following this approach means we'll
need to override the sqlalchemy initialization method.

Therefore, as a preparation to the Turbogears2 migration, already change the
database reference string under Pylons.
When upgrading to a version of Kallithea containing this commit, the .ini
file will manually need to be adapted to remove the .db1 strings.

db: script to test database upgrades

dbmigrate-test executes Alembic upgrade scripts between two Kallithea
versions in a clean environment. There is no automated testing of
whether the upgraded database is functional, only that the upgrade
proceeds without errors.