Add warning for end_date later than 2024-07-21 in DIVI data

[lenaploetzke]

Motivation / Current Behaviour

There is currently no restriction regarding the end date in the DIVI data. Recently it was announced via github that our used source 'Intensivregister_Landkreise_Kapazitaeten.csv' will no longer be updated. See also https://github.com/robert-koch-institut/Intensivkapazitaeten_und_COVID-19-Intensivbettenbelegung_in_Deutschland/issues/13.

Enhancement description

A warning should be displayed if the end date is after the announced end date.

Additional context

At the moment, it seems that the divi data set is still being updated. Nevertheless, the latest data should be used with caution.

Checklist

• [X] Attached labels, especially loc:: or model:: labels.
• [X] Linked to project