Fix small error in Variant doc #26562

Job	Run time
📊 Static checks / Code style, file formatting, and docs	3m 47s
🍎 macOS / Editor (target=editor, tests=yes)	6m 27s
🍏 iOS / Template (target=template_release)	2m 15s
🍎 macOS / Template (target=template_release)	3m 22s
🏁 Windows / Editor (target=editor, tests=yes)	9m 7s
🏁 Windows / Template (target=template_release)	7m 49s
🐧 Linux / Editor w/ Mono (target=editor)	6m 15s
🌐 Web / Template w/ threads (target=template_release, threads=yes)	4m 37s
🐧 Linux / Editor with doubles and GCC sanitizers (target=editor, tests=yes, dev_build=yes, scu_build=yes, precision=double, use_asan=yes, use_ubsan=yes, linker=gold)	17m 0s
🌐 Web / Template w/o threads (target=template_release, threads=no)	4m 24s
🤖 Android / Template (target=template_release)	4m 12s
🐧 Linux / Editor with clang sanitizers (target=editor, tests=yes, dev_build=yes, use_asan=yes, use_ubsan=yes, use_llvm=yes, linker=lld)	6m 23s
🐧 Linux / Editor with ThreadSanitizer (target=editor, tests=yes, dev_build=yes, use_tsan=yes, use_llvm=yes, linker=lld)	7m 57s
🐧 Linux / Template w/ Mono (target=template_release)	1m 30s
🐧 Linux / Minimal template (target=template_release, everything disabled)	2m 21s
🪲 Godot CPP / Build and test Godot CPP	7m 5s
	1h 34m 31s

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