regression in URL.build(…,port="")

[commonism]

Describe the bug

Input filtering for with_port #793 changed the logic to render the URL to compare the port to None.
94b8679#r116844287
as it is possible to create a URL with a port="" via URL.build, this results in urls created with an empty port.

To Reproduce

import yarl
u = yarl.URL.build(scheme="http", host="api.com", port="", path="/v1")
assert str(u) == "http://api.com/v1", str(u)

Expected behavior

Filtering port="" in URL.build.
I'd even prefer to allow "" and convert to None to stay backwards compatible.

Logs/tracebacks

AssertionError: http://api.com:/v1

Python Version

$ python --version
Python 3.10.6

multidict Version

$ python -m pip show multidict
Name: multidict
Version: 6.0.2

yarl Version

$ python -m pip show yarl
Name: yarl
Version: 1.9.2

OS

Linux

Additional context

No response

Code of Conduct

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

[webknjaz]

Hello, please contribute regression tests via PR to move things along.