Use `Packed*Array` over `Vector<T>` in TypedArray #21813

Job	Run time
📊 Static checks / Code style, file formatting, and docs	43s
🐧 Linux / Editor w/ Mono (target=editor)	34m 27s
🐧 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)	35m 56s
🍏 iOS / Template (target=template_release)	12m 49s
🐧 Linux / Editor with clang sanitizers (target=editor, tests=yes, dev_build=yes, use_asan=yes, use_ubsan=yes, use_llvm=yes, linker=lld)	31m 37s
🍎 macOS / Editor (target=editor, tests=yes)	22m 56s
🍎 macOS / Template (target=template_release)	27m 56s
🐧 Linux / Editor with ThreadSanitizer (target=editor, tests=yes, dev_build=yes, use_tsan=yes, use_llvm=yes, linker=lld)	28m 26s
🌐 Web / Template w/ threads (target=template_release, threads=yes)	21m 38s
🌐 Web / Template w/o threads (target=template_release, threads=no)	21m 29s
🐧 Linux / Template w/ Mono (target=template_release)	16m 6s
🐧 Linux / Minimal template (target=template_release, everything disabled)	11m 29s
🤖 Android / Template (target=template_release)	28m 42s
🏁 Windows / Editor (target=editor, tests=yes)	42m 22s
🏁 Windows / Template (target=template_release)	29m 49s
🪲 Godot CPP / Build and test Godot CPP	6m 47s
	6h 13m 12s

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