chore(deps): update rust crate regex to 1.12.2 #844

Job	Run time
cargo shear (unused dependencies)	14s
Unit, docs and onhost integration tests	8m 24s
Build release binaries	6m 18s
ubuntu / stable / coverage	3m 36s
cargo clippy	1m 58s
K8s integration tests (part2)	10m 40s
K8s integration tests (part1)	13m 10s
tests as root	3m 59s
Unit test for embedded downloader	27s
K8s integration tests (flux-self-update)	10m 52s
codespell	8s
⚖️ Check third party licenses	4m 40s
cargo fmt	14s
cargo doc	1m 43s
build-widows-binary	8m 33s
security / Rust audit scanner	2m 52s
k8s-e2e-tests / K8s e2e tests infra	11m 23s
k8s-e2e-tests / K8s e2e tests	4s
🟢 All required checks and tests pass	4s
	1h 29m 19s

Provide feedback