Merge branch '443-haystack-exceptions-missingdependency-the-whoosh-backend-requires-the-installation-of-whoosh' into 'master'

Resolve "haystack.exceptions.MissingDependency: The 'whoosh' backend requires the installation of 'Whoosh'."

Closes #443

See merge request !602

Resolve "Handle broken DashboardWidgets correctly"

Closes #368

See merge request !477

Resolve "Fix core permissions"

Closes #433

See merge request !598

Merge branch '434-remove-django-settings-context-processor-and-define-better-ways-to-handl-the-values-it-passes' into 'master'

Resolve "Remove django-settings-context-processor and define better ways to handl the values it passes"

Closes #434

See merge request !600

Remove Pillow as direct dependency

See merge request !599

Add missing dependency. Closes AlekSIS#24

Closes AlekSIS#24

See merge request !592

Set default_auto_field to BigAutoField and fix migrations

See merge request !596

Resolve "Drop Python <3.9 compatibility"

Closes #420

See merge request !594

Rationale: We drop Python <3.9 support

Rationale: We drop support for Python <3.9

Update poetry.lock

See merge request !597

Protect celery-progress endpoint

Closes #379

See merge request !595

Resolve "Correctly implement the ckeditor"

Closes #340

See merge request !585

Resolve "PDF is rendered without request in context"

Closes #430

See merge request !588

Resolve "Make django-cachalot compatible with Django 3.2"

Closes #426

See merge request !587

Merge branch '432-synchronisation-between-aleksis-and-django-groups-works-incompletely' into 'master'

Resolve "Synchronisation between AlekSIS and Django groups works incompletely"

Closes #432

See merge request !590