Unhandled exception (IndexError) in URL parsing

[lenix123]

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Describe the bug

We were fuzzing URL() parser and have found IndexError.

To Reproduce

1. install yarl 1.18.3:

pip install --force-reinstall -v "yarl==1.18.3"

2. reproduce IndexError:

from yarl import URL
URL("//]'z[")

Expected behavior

Parse string without an error

Logs/tracebacks

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.10/dist-packages/yarl/_url.py", line 355, in __new__
    return pre_encoded_url(val) if encoded else encode_url(val)
  File "/usr/local/lib/python3.10/dist-packages/yarl/_url.py", line 147, in encode_url
    scheme, netloc, path, query, fragment = split_url(url_str)
  File "/usr/local/lib/python3.10/dist-packages/yarl/_parse.py", line 72, in split_url
    if bracketed_host[0] == "v":
IndexError: string index out of range

Python Version

$ python --version
Python 3.10.12

multidict Version

$ python -m pip show multidict
Version: 6.2.0

propcache Version

$ python -m pip show propcache
Version: 0.3.0

yarl Version

$ python -m pip show yarl
Version: 1.18.3

OS

Ubuntu:22.04

Additional context

No response

[webknjaz]

Expected behavior

Parse string without an error

FTR, I think this expectation is incorrect, and the behavior should be raising a ValueError which #1512 attempts to implement. @lenix123 or do you have a justification for it to being parsed in a specific way?