Bump development tools: mypy, codespell, isort, ...

Move all tools configuration in pyproject.toml.

Remove no longer needed mypy overrides.

Scheduler temporary backend has been removed in favor of a
more efficient memory backend.

For now this information is not used downstream, but it can be useful
for specific analysis or one-shot scheduling.

The oldest part of the scheduler API was updated to use model classes
(based on attr package) instead of dictionaries in order to improve
typing.

As the types-beautifulsoup4 package gets installed in the swh virtualenv
as it is a swh-scanner test dependency, some mypy errors were reported
related to beautifulsoup4 typing.

As the returned type for the find method of bs4 is the following union:
Tag | NavigableString | None, isinstance calls must be used to ensure
proper typing which is not great.

So prefer to use the select_one method instead where a simple None check
must be done to ensure typing is correct as it is returning Optional[Tag].
In a similar manner, replace use of find_all method by select method.

It also has the advantage to simplify the code.

Remove use of --import-mode=importlib pytest option and use
new option consider_namespace_packages to fix tests execution
with latest pytest release.

It fixes installation of dependencies required by swh-scheduler pytest plugin.

This module introduce Julia Lister.
It retrieves Julia packages origins from the Julia General Registry, a Git
repository made of per package directory with Toml definition files.

Previously, the lister was relying on the use of the CRANtools R module
but it has the drawback to only list the latest version of each registered
package in the CRAN registry.

In order to get all possible versions for each CRAN package, prefer to exploit
the content of the weekly dump of the CRAN database in RDS format.

To read the content of the RDS file from Python, the rpy2 package is used as
it has the advantage to be packaged in debian.

Related to swh/meta#1709.

pytest-postgresql 3.1.3 and pytest-redis 2.4.0 added support for
pytest >= 7 so we can now drop the pytest pinning.

Related to T3916

Legacy Lister classes from the swh.lister.core mdule are no longer
used in swh-lister codebase so it is time to remove them.

Also remove lister CLI options related to legacy Lister API.

As a consequence, the following requirements are no longer needed:
arrow, SQLAlchemy, sqlalchemy-stubs and testing.postgresql.

Closes T2442

The new lister has incremental and full listing capability.
It can request the Bitbucket API in anonymous and HTTP basic authentication
modes. Rate-limiting is not aggressive and is handled.

Without the following, and the new swh.scheduler bump, some dependencies were
no longer resolved properly.

Related to T2746

instead of pytest-postgresql which is a transitive dependency from swh.core[db]

Related to T2746

Listers are declared as plugins via the `swh.workers` entry_point.

As such, the registry function is expected to return a dict with the
`task_modules` field (as for generic worker plugins), plus:

- `lister`: the lister class,
- `models`: list of SQLAlchemy models used by this lister,
- `init` (optionnal): hook (callable) used to initialize the lister's state
  (typically, create/initialize the database for this lister).
  If not set, the default implementation creates database tables (after
  optionally having deleted exisintg ones) according to models declared in
  the `models` register field.

There is no need for explicitely add lister task modules in the main
`conftest` module, but any new/extra lister to be tested must be registered
(the tested lister module must be properly installed in the test environment).

Also refactor a bit the cli tools:
- add support for the standard --config-file option at the 'lister' group
  level,
- move the --db-url to the 'lister' group,
- drop the --lister option for the `swh lister db-init` cli tool:
  initializing (especially with --drop-tables) the database for a single
  lister is unreliable, since all tables are created using a sibgle MetaData
  (in the same namespace).

pytest<4 because of https://github.com/pytest-dev/pytest/issues/4641