Fix #14941: FN memleak with `_create_locale` (#8758) #20512

Job	Run time
build_cmake (ubuntu:25.10, true, true)	5m 5s
build_cmake (alpine:3.23, false, false)	4m 27s
build_cmake (ubuntu:24.04, true, true)	5m 18s
build_make (ubuntu:25.10)	5m 6s
build_make (alpine:3.23)	4m 59s
build_make (ubuntu:24.04)	4m 33s
	29m 28s

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