Please confirm the following

• I agree to follow the aio-libs Code of Conduct

• I have checked the current issues for duplicates.

• I understand this is open source software provided for free and that I might not receive a timely response.
• I am positive I am NOT reporting a (potential) security
  vulnerability, to the best of my knowledge. (These must be shared by
  submitting this report form instead, if
  any hesitation exists.)

• I am willing to submit a pull request with reporoducers as xfailing test cases or even entire fix. (Assign this issue to me.)

Describe the bug

Calling with_suffix always re-encode the entire name. That's because with_suffix calls with_name under the hood, which always auto encodes

from the method's description:

suffix is encoded if needed

To Reproduce

from yarl import URL
url = URL("https://domain.com/video file.mp4")
print (url) # https://domain.com/video%20file.mp4
print (url.with_suffix(".avi")) # https://domain.com/video%2520file.avi

Expected behavior

Only the suffix should be encoded (if needed) instead of the entire name.

Therefore, the expected result would be https://domain.com/video%20file.avi instead of https://domain.com/video%2520file.avi

Logs/tracebacks

NA

Python Version

$ python --version
Python 3.13.2

multidict Version

$ python -m pip show multidict
Version: 6.1.0

propcache Version

$ python -m pip show propcache
Version: 0.2.1

yarl Version

$ python -m pip show yarl
Version: 1.18.3

OS

Windows 10

Additional context

No response