[macOS] Fix `generate_bundle` build flag for .NET builds. #36127

Job	Run time
📊 Static checks / Code style, file formatting, and docs	1m 2s
🐧 Linux / Editor w/ Mono (target=editor)	6m 14s
🤖 Android / Editor (target=editor)	24m 58s
🍏 iOS / Template (target=template_release)	10m 40s
🐧 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)	18m 53s
🤖 Android / Template arm32 (target=template_release, arch=arm32)	17m 5s
🐧 Linux / Editor with clang sanitizers (target=editor, tests=yes, dev_build=yes, use_asan=yes, use_ubsan=yes, use_llvm=yes, linker=lld)	35m 24s
🐧 Linux / Editor with ThreadSanitizer (target=editor, tests=yes, dev_build=yes, use_tsan=yes, use_llvm=yes, linker=lld)	32m 27s
🌐 Web / Template w/ threads (target=template_release, threads=yes)	25m 25s
🐧 Linux / Template w/ Mono (target=template_release)	2m 59s
🍎 macOS / Editor (target=editor, tests=yes)	29m 55s
🌐 Web / Template w/o threads (target=template_release, threads=no)	25m 47s
🐧 Linux / Minimal template (target=template_release, everything disabled)	2m 23s
🍎 macOS / Template (target=template_release)	20m 33s
🤖 Android / Template arm64 (target=template_release, arch=arm64)	16m 52s
🏁 Windows / Editor (target=editor, tests=yes)	47m 16s
🏁 Windows / Template (target=template_release)	35m 43s
🪲 Godot CPP / Build and test Godot CPP	8m 0s
	6h 1m 36s

Provide feedback