Revert "Merge branch 'renovate/django-phonenumber-field-7.x' into 'master'"

See merge request !1157

This reverts merge request !1093

By the powers of the almighty Aleksolotl

See merge request !1152

Update dependency django-phonenumber-field to v7

See merge request !1093

Update dependency django-maintenance-mode to ^0.18.0

See merge request !1116

Update dependency django-allauth to ^0.52.0

See merge request !1134

Bump dev version to 3.0.dev3

See merge request !1153

Reformat

See merge request !1150

Translations update from Weblate

See merge request !1139

Currently translated at 71.0% (81 of 114 strings)

Translation: AlekSIS/AlekSIS-Core-Frontend
Translate-URL: https://translate.edugit.org/projects/aleksis/aleksis-core-frontend/uk/

Translations update from Weblate

See merge request !1138

Currently translated at 100.0% (715 of 715 strings)

Translation: AlekSIS/AlekSIS-Core
Translate-URL: https://translate.edugit.org/projects/aleksis/aleksis-core/de/

Update translation files

See merge request !1151

Remove debug print

See merge request !1146

Automatically allow CORS from ALLOWED_HOSTS and dev servers

Closes #772

See merge request !1142

Also, set base URL to not include the scheme

Use new, generic mechanism for registration of classes

See merge request !1144

Drop legacy iCal feed stuff

See merge request !1145

Merge branch '778-migrations-fail-when-chronos-is-installed-no-migrations-were-ever-run-before' into 'master'

Resolve "Migrations fail when Chronos is installed & no migrations were ever run before"

Closes #778

See merge request !1141

Resolve "Fix/improve route generation management command"

Closes #779

See merge request !1143

Resolve "[Data checks] Replace all occurences of check with data_check"

Closes #775

See merge request !1140