Build a widget that fetches birth year data from an API and plots it on a histogram.

Requirements:

1. Fetch data from an API endpoint (you can mock with https://dummyjson.com/users which has birthDate).
2. Extract the birth year from each user’s birthDate.
3. Count how many people were born in each year.
4. Display the counts in a simple histogram (bars with heights corresponding to counts).
5. Include axis labels for clarity.
6. Focus on functionality over styling.