Add a link to the DSF 2024 impact report on donate and about pages

[sarahboyce]

There is a published DSF 2024 impact report

I think this should be prominently linked in the:

• "Why give to the Django Software Foundation" section of the donate page: https://www.djangoproject.com/fundraising/
• near the top of the DSF about page: https://www.djangoproject.com/foundation/

This link could be dynamic to show the latest DSF report so it doesn't need to be updated each year (hoping we continue to publish).

The current DSF donation page points to Fellow summaries from the first 3 months of the program, 2016 and 2017.
As a bonus, it would be good to have a link to the Fellow section of the 2024 report within that paragraph: https://www.djangoproject.com/foundation/reports/2024/#fellows-highlights

Note that I believe updates to the fundraising page can be done here: https://github.com/django/djangoproject.com/blob/main/djangoproject/templates/fundraising/index.html

But updates to the DSF about page might be flatpage content which requires someone with permissions.