Resolve "Favicon should contain only school bag"

Closes #254

See merge request !772

# Conflicts:
#   CHANGELOG.rst

Resolve "Icons/logo should be uploaded to public/"

Closes #581

See merge request !837

# Conflicts:
#   CHANGELOG.rst

Resolve ""Imprint" is called "imprint""

Closes #579

See merge request !834

# Conflicts:
#   CHANGELOG.rst

Resolve "Colours not updated / stylesheet not regenerated on preferences save"

Closes #575

See merge request !836

Resolve "Make database ssl mode configurable"

Closes #578

See merge request !833

Fix typos

See merge request !832

Update dependency django-auth-ldap to v4

See merge request !827

Release 2.3.1

See merge request !830

Resolve "Error uploading favicon to S3"

Closes #576

See merge request !829

Add t.teichler@babiel.com to mailmap

See merge request !826

Prepare release 2.3

See merge request !825

Resolve "Place of birth is None if unset"

Closes #571

See merge request !823

Fix optional dependency on sentry-sdk

Closes #573

See merge request !821