Support uppercase characters in host

[xZise]

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Describe the bug

When using uppercase characters in the hostname they get reported as invalid:

>>> URL.build(scheme="http", host="A", port=port, path="/")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "...\yarl\_url.py", line 386, in build
    _host = _encode_host(host, validate_host=True)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "...\yarl\_url.py", line 1496, in _encode_host
    raise ValueError(
ValueError: Host 'A' cannot contain 'A' (at position 0)
>>> URL.build(scheme="http", host="a", port=port, path="/")
URL('http://a/')

It appears to me, that there needs to be a conversion into lowercase, for example the host-property says it gets converted to lowercase (which is the case when using __init__()) and the comment at NOT_REG_NAME mentions that it only accepts lowercase ASCII values:

# this pattern matches anything that is *not* in those classes. and is only used
# on lower-cased ASCII values.

When using a non-ASCII string with host, it gets encoded so it seems weird that ASCII uppercase strings aren't "encoded" into lowercase. There is #386, but there it is using __init__() which works correctly.

To Reproduce

1. Install yarl
2. Call yarl.URL.build(scheme="http", host="A", port=port, path="/")

Expected behavior

A valid URL which is identical to the build URL using the lowercase host.

Logs/tracebacks

>>> URL.build(scheme="http", host="A", port=port, path="/")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "...\yarl\_url.py", line 386, in build
    _host = _encode_host(host, validate_host=True)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "...\yarl\_url.py", line 1496, in _encode_host
    raise ValueError(
ValueError: Host 'A' cannot contain 'A' (at position 0)
>>> URL.build(scheme="http", host="a", port=port, path="/")
URL('http://a/')

Python Version

$ python --version
Python 3.12.2

multidict Version

$ python -m pip show multidict
Name: multidict
Version: 6.1.0
Summary: multidict implementation
Home-page: https://github.com/aio-libs/multidict
Author: Andrew Svetlov
Author-email: andrew.svetlov@gmail.com
License: Apache 2
Location: ..\Lib\site-packages
Requires:
Required-by: yarl

propcache Version

$ python -m pip show propcache
Name: propcache
Version: 0.2.0
Summary: Accelerated property cache
Home-page: https://github.com/aio-libs/propcache
Author: Andrew Svetlov
Author-email: andrew.svetlov@gmail.com
License: Apache-2.0
Location: ..\Lib\site-packages
Requires:
Required-by: yarl

yarl Version

$ python -m pip show yarl
Name: yarl
Version: 1.18.0
Summary: Yet another URL library
Home-page: https://github.com/aio-libs/yarl
Author: Andrew Svetlov
Author-email: andrew.svetlov@gmail.com
License: Apache-2.0
Location: ..\Lib\site-packages
Requires: idna, multidict, propcache
Required-by:

OS

Windows 10

Additional context

No response

[bdraco]

We do lowercase the host after the validation so its an order problem.

[bdraco]

This is a regression introduced in #954

[bdraco]

#1442 will fix this.

Unfortunately we cannot do a release right now due to pypa/gh-action-pypi-publish#307

[bdraco]

It looks like whatever problem that was slowing down the uploads enough to fail has been resolved as propcache just released successfully. I'll try to get a .3 published with this fix today

[bdraco]

1.18.3 publishing now. 🤞 that the upload problem doesn't bite us

https://github.com/aio-libs/yarl/actions/runs/12108501591

[bdraco]

1.18.3 now available with the fix