Fix handling of visibility with nested OptionGroups. #270

Job	Run time
CMake Build	51s
Validate Format Config	13s
Test / macOS (Xcode 26.0 - sequoia - ARM64)	1m 4s
Test / Swift SDK for Wasm Build (nightly-main - jammy)	1m 9s
Test / macOS (Xcode 16.4 - sequoia - ARM64)	1m 7s
Test / Swift SDK for Wasm Build (nightly-6.3 - jammy)	1m 9s
Test / Swift SDK for Wasm Build (6.2 - jammy)	1m 11s
Test / Linux (6.1 - jammy - x86_64)	1m 24s
Test / Linux (6.2 - jammy - x86_64)	1m 29s
Test / Windows (6.1 - windows-2022)	8m 38s
Test / Linux (nightly-6.3 - jammy - x86_64)	1m 42s
Test / Linux (5.9 - jammy - x86_64)	1m 7s
Test / Linux (nightly-main - jammy - x86_64)	1m 41s
Test / Linux (5.10 - jammy - x86_64)	1m 5s
Test / Windows (6.0 - windows-2022)	8m 10s
Test / Linux ( - - aarch64)	14s
Test / Windows (nightly-main - windows-2022)	10m 27s
Test / Linux (6.0 - jammy - x86_64)	1m 13s
Test / Windows (nightly-6.3 - windows-2022)	9m 55s
Test / Windows (6.2 - windows-2022)	8m 44s
Soundness / Documentation check	1m 17s
Soundness / Unacceptable language check	6s
Soundness / API breakage check	1m 29s
Soundness / Format check	44s
Soundness / YAML lint check	5s
Soundness / License headers check	9s
Soundness / Broken symlinks check	7s
Test / macOS (Xcode 16.3 - sequoia - ARM64)	2m 30s
Soundness / Python lint check	8s
Soundness / Shell check	-1s
	1h 9m 7s

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