Fixes #7949 .

Description

Regardless of the type of weight map, random numbers should be kept as floating-point numbers for calculating the sampling location. However, searchsorted requires matching data structures. I have modified convert_to_dst_type to control converting only the data structure while maintaining the original data type. Additionally, I have included an example with integer weight maps in the test file.

Types of changes

• Non-breaking change (fix or new feature that would not break existing functionality).
• Breaking change (fix or new feature that would cause existing functionality to change).
• New tests added to cover the changes.
• Integration tests passed locally by running ./runtests.sh -f -u --net --coverage.
• Quick tests passed locally by running ./runtests.sh --quick --unittests --disttests.
• In-line docstrings updated.
• Documentation updated, tested make html command in the docs/ folder.