devel/py-ufmt: Add py-ufmt 2.5.1

ufmt is a safe, atomic code formatter for Python built on top of black and
usort:
- Black makes code review faster by producing the smallest diffs possible.
  Blackened code looks the same regardless of the project you're reading.
- usort is a safe, minimal import sorter. Its primary goal is to make no
  "dangerous" changes to code, and to make no changes on code style.

ufmt formats files in-memory, first with usort and then with black, before
writing any changes back to disk. This enables a combined, atomic step in CI/CD
workflows for checking or formatting files, without any chance of conflict or
intermediate changes between the import sorter and the code formatter.