Deprecate `project_settings_changed` signal #8235

Job	Run time
📊 Static checks / Code style, file formatting, and docs	1m 1s
🐧 Linux / Editor w/ Mono (target=editor)	38m 24s
🐧 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)	45m 18s
🐧 Linux / Editor with clang sanitizers (target=editor, tests=yes, dev_build=yes, use_asan=yes, use_ubsan=yes, use_llvm=yes, linker=lld)	41m 3s
🐧 Linux / Editor with ThreadSanitizer (target=editor, tests=yes, dev_build=yes, use_tsan=yes, use_llvm=yes, linker=lld)	34m 22s
🐧 Linux / Template w/ Mono (target=template_release)	47m 8s
🐧 Linux / Minimal template (target=template_release, everything disabled)	30m 56s
🍏 iOS / Template (target=template_release)	23m 33s
🤖 Android / Template (target=template_release)	56m 2s
🍎 macOS / Editor (target=editor, tests=yes)	48m 43s
🍎 macOS / Template (target=template_release)	5m 38s
🌐 Web / Template (target=template_release)	1m 18s
🏁 Windows / Editor (target=editor, tests=yes)	1h 38m 42s
🏁 Windows / Template (target=template_release)	24m 4s
🪲 Godot CPP / Build and test Godot CPP	11m 28s
	8h 27m 40s

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