Merge branch 'prepare-release-2.0' into 'release/2.0'

CHANGELOG.rst

aleksis/apps/untis/commands.py

.../apps/untis/management/commands/move_dates_for_testing.py

aleksis/apps/untis/management/commands/untis_import_mysql.py

.../apps/untis/management/commands/untis_import_mysql_all.py

.../management/commands/untis_import_mysql_current_future.py

...is/management/commands/untis_import_mysql_current_next.py

...ps/untis/management/commands/untis_import_mysql_future.py

aleksis/apps/untis/tasks.py

fixtures/README.rst

fixtures/multiuser-2022.sql

poetry.lock

pyproject.toml