fix(sinks): confinement follow-ups from #25820 codex review #58653

Job	Run time
changes / source	7s
changes / int_tests	-1s
Check code format	3m 21s
Check clippy	7m 44s
Build VRL Playground	4m 55s
VRL - Linux	3m 34s
Check events	1m 41s
Check Generated Docs	10m 42s
Check Cue docs	3m 20s
Check Rust Docs	6m 55s
Check Markdown	2m 53s
test / Tests	13m 22s
Check scripts	0s
Check that the 3rd-party license file is up to date	0s
changes / e2e_tests	-10s
Test Suite	3s
	58m 26s

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