test: fix flaky `test_request_queue_unlock_requests` #609

Job	Run time
Code checks / Spell check	5s
PR title check	6s
Tests / Integration tests (3.14, ubuntu-latest)	2m 32s
Code checks / Actions lint check	30s
Docstrings checks / Docstrings checks	17s
Doc checks / Doc checks / Docs check	1m 0s
Tests / Integration tests (3.11, ubuntu-latest)	2m 24s
Code checks / Type check / Type check (3.11)	9s
Code checks / Type check / Type check (3.12)	13s
Code checks / Lint check / Lint check (3.13)	14s
Code checks / Lint check / Lint check (3.11)	8s
Tests / Unit tests / Unit tests (ubuntu-latest, 3.12)	43s
Tests / Unit tests / Unit tests (windows-latest, 3.13)	1m 11s
Tests / Unit tests / Unit tests (windows-latest, 3.11)	1m 12s
Code checks / Lint check / Lint check (3.14)	16s
Code checks / Type check / Type check (3.14)	13s
Tests / Unit tests / Unit tests (ubuntu-latest, 3.14)	48s
Tests / Unit tests / Unit tests (windows-latest, 3.12)	1m 14s
Code checks / Lint check / Lint check (3.12)	11s
Tests / Unit tests / Unit tests (ubuntu-latest, 3.11)	46s
Code checks / Type check / Type check (3.13)	13s
Tests / Unit tests / Unit tests (ubuntu-latest, 3.13)	44s
Tests / Unit tests / Unit tests (windows-latest, 3.14)	1m 3s
	16m 12s

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