chore(htmx): finalize contrib.htmx removal residue #6849

Job	Run time
mypy	37s
validate	15s
slotscheck	16s
pyright	39s
Test server integration (uvicorn>=0.27.0)	48s
Test server integration (uvicorn<0.27.0)	45s
Test Minimal Application with Base Dependencies	17s
test_typing_extensions (4.13.1)	21s
test_typing_extensions (latest)	23s
test_typing_extensions (4.14.0)	18s
test_typing_extensions (4.12.1)	18s
test (3.12) / test	2m 25s
test (3.11) / test	2m 10s
test (3.13) / test	2m 21s
test (3.14) / test	1m 57s
test-platform-compat	0s
build-docs	2m 33s
test_success	4s
upload-test-coverage	17s
	16m 44s

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