LibUnicode: Gate Rust IDNA bindings behind a feature #33367

Job	Run time
Linux, arm64, Sanitizer, Clang / CI	19m 9s
Windows, x86_64, Sanitizer, ClangCL / CI	34m 58s
Linux, x86_64, Release, GNU / CI	5m 6s
Linux, x86_64, Fuzzers, Clang / CI	4m 8s
macOS, arm64, Sanitizer, Clang / CI	33m 8s
Linux, x86_64, Sanitizer, Clang / CI	19m 0s
Linux, x86_64, All_Debug, Clang / CI	17m 2s
	2h 12m 31s

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