Fix TabContainer not redrawing after toggling tab icon #28179

Job	Run time
📊 Static checks / Code style, file formatting, and docs	3m 44s
🍏 iOS / Template (target=template_release)	45m 20s
🍎 macOS / Editor (target=editor, tests=yes)	57m 2s
🐧 Linux / Editor w/ Mono (target=editor)	37m 47s
🍎 macOS / Template (target=template_release)	42m 28s
🤖 Android / Template (target=template_release)	30m 3s
🐧 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)	40m 12s
🌐 Web / Template w/ threads (target=template_release, threads=yes)	22m 12s
🌐 Web / Template w/o threads (target=template_release, threads=no)	22m 25s
🐧 Linux / Editor with clang sanitizers (target=editor, tests=yes, dev_build=yes, use_asan=yes, use_ubsan=yes, use_llvm=yes, linker=lld)	34m 2s
🏁 Windows / Editor (target=editor, tests=yes)	45m 22s
🏁 Windows / Template (target=template_release)	31m 48s
🐧 Linux / Editor with ThreadSanitizer (target=editor, tests=yes, dev_build=yes, use_tsan=yes, use_llvm=yes, linker=lld)	30m 50s
🐧 Linux / Template w/ Mono (target=template_release)	24m 18s
🐧 Linux / Minimal template (target=template_release, everything disabled)	15m 1s
🪲 Godot CPP / Build and test Godot CPP	6m 57s
	8h 9m 31s

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