fix(typing): Fix typing in websocket listener class #4166

Job	Run time
validate	19s
pyright	2m 6s
mypy	2m 21s
slotscheck	1m 37s
Test server integration (uvicorn<0.27.0)	1m 41s
Test Minimal Application with Base Dependencies	1m 18s
Test server integration (uvicorn>=0.27.0)	1m 31s
Test Minimal Pydantic 1 application	1m 36s
test-platform-compat	0s
test (3.10) / test	2m 57s
test (3.11) / test	2m 29s
test (3.12) / test	3m 50s
test (3.8) / test	3m 51s
test (3.9) / test	2m 53s
build-docs	3m 31s
codeql	2m 57s
upload-test-coverage	22s
sonar	0s
	35m 19s

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