Cleanup regexp usages #11830

Job	Run time
build_opam (4.14.x)	9m 16s
build_js	2m 0s
build_opam (5.2.x)	5m 13s
build_details	5s
build_win32 (x64)	17m 49s
build_no_depopts	5m 57s
lezer_parse	51s
build_posix (debian_trixie, amd64)	14m 52s
build_posix (debian_bookworm, amd64)	14m 35s
run_tests (@citest)	13m 19s
build_posix (ubuntu_oracular, amd64)	14m 56s
tree_sitter_parse	51s
run_tests (@doctest)	8m 23s
update_doc	0s
build_posix (ubuntu_noble, amd64)	14m 25s
run_tests (@mediatest)	12m 39s
build_posix (alpine, amd64)	12m 46s
fetch_s3_artifacts	20s
build_docker_minimal (amd64)	2m 21s
build_docker_alpine_minimal (amd64)	57s
build_docker (amd64)	3m 9s
build_docker_alpine (amd64)	1m 2s
update_release	0s
build_docker_release-minimal	0s
build_docker_release	0s
	2h 35m 46s

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