PYTHON-5773 Coverage increase for `uri_parser_shared.py` #9459

Job	Run time
CPython pypy-3.11-ubuntu-latest	14m 1s
CPython 3.13t-ubuntu-latest	13m 39s
Test minimum dependencies and Python	53s
DocTest	1m 2s
Coverage	13m 55s
Make an sdist	22s
Integration Tests	56s
Link Check	3m 39s
Typing Tests (3.10)	1m 4s
Typing Tests (3.11)	1m 1s
static	2m 57s
Docs Checks	40s
CPython 3.10-ubuntu-latest	13m 9s
Install from SDist and Test	1m 3s
	1h 8m 21s

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