Resolve "[S3] Upload of icons still fails"

Closes #621

See merge request !914

Get file object from preferences instead from signal for generating favicons after preference change

Show home and mobile phone numbers

See merge request !913

Resolve "Phone number in person detail not properly linked"

Closes #618

See merge request !912

Resolve "[Signup] Permission denied also if signup is enabled"

Closes #615

See merge request !911

Do release 2.6

See merge request !904

These will go into the global documentation

Translations update from Weblate

See merge request !903

Currently translated at 100.0% (646 of 646 strings)

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

Update translation files

See merge request !902

Translations update from Weblate

See merge request !867

Resolve "Provide base templates for e-mails generated by apps"

Closes #439

See merge request !874

Update dependency pycountry to v22

See merge request !900

[Docs] Remove hairspace in licence to ease LaTeX builds

See merge request !901

Re-merge handbook

See merge request !898