Allow registering "runtime classes" in modules (not just GDExtension) #23592

Job	Run time
📊 Static checks / Code style, file formatting, and docs	32s
🍎 macOS / Editor (target=editor, tests=yes)	17m 48s
🍎 macOS / Template (target=template_release)	26m 52s
🐧 Linux / Editor w/ Mono (target=editor)	32m 8s
🐧 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)	27m 10s
🍏 iOS / Template (target=template_release)	25m 34s
🐧 Linux / Editor with clang sanitizers (target=editor, tests=yes, dev_build=yes, use_asan=yes, use_ubsan=yes, use_llvm=yes, linker=lld)	28m 10s
🤖 Android / Template (target=template_release)	26m 30s
🐧 Linux / Editor with ThreadSanitizer (target=editor, tests=yes, dev_build=yes, use_tsan=yes, use_llvm=yes, linker=lld)	25m 48s
🐧 Linux / Template w/ Mono (target=template_release)	19m 44s
🌐 Web / Template w/ threads (target=template_release, threads=yes)	18m 28s
🐧 Linux / Minimal template (target=template_release, everything disabled)	14m 5s
🏁 Windows / Editor (target=editor, tests=yes)	39m 13s
🌐 Web / Template w/o threads (target=template_release, threads=no)	18m 47s
🏁 Windows / Template (target=template_release)	26m 8s
🪲 Godot CPP / Build and test Godot CPP	6m 50s
	5h 53m 47s

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