GDExtension: Fix missing library path breaking hot reloading #28202

Job	Run time
📊 Static checks / Code style, file formatting, and docs	3m 33s
🍏 iOS / Template (target=template_release)	16m 30s
🤖 Android / Template (target=template_release)	30m 13s
🍎 macOS / Editor (target=editor, tests=yes)	1h 4m 27s
🍎 macOS / Template (target=template_release)	19m 9s
🌐 Web / Template w/ threads (target=template_release, threads=yes)	22m 34s
🏁 Windows / Editor (target=editor, tests=yes)	44m 22s
🌐 Web / Template w/o threads (target=template_release, threads=no)	22m 27s
🏁 Windows / Template (target=template_release)	33m 8s
🐧 Linux / Editor w/ Mono (target=editor)	37m 56s
🐧 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)	37m 53s
🐧 Linux / Editor with clang sanitizers (target=editor, tests=yes, dev_build=yes, use_asan=yes, use_ubsan=yes, use_llvm=yes, linker=lld)	33m 58s
🐧 Linux / Editor with ThreadSanitizer (target=editor, tests=yes, dev_build=yes, use_tsan=yes, use_llvm=yes, linker=lld)	30m 33s
🐧 Linux / Template w/ Mono (target=template_release)	25m 37s
🐧 Linux / Minimal template (target=template_release, everything disabled)	13m 49s
🪲 Godot CPP / Build and test Godot CPP	7m 1s
	7h 23m 10s

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