Run resource previewer on the main thread if using GL compatibility #19805

Job	Run time
📊 Static checks / Code style, file formatting, and docs	38s
🍏 iOS / Template (target=template_release)	16m 40s
🤖 Android / Template (target=template_release)	27m 36s
🍎 macOS / Editor (target=editor, tests=yes)	30m 22s
🐧 Linux / Editor w/ Mono (target=editor)	34m 2s
🍎 macOS / Template (target=template_release)	25m 11s
🐧 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)	17m 23s
🐧 Linux / Editor with clang sanitizers (target=editor, tests=yes, dev_build=yes, use_asan=yes, use_ubsan=yes, use_llvm=yes, linker=lld)	6m 45s
🌐 Web / Template (target=template_release)	18m 12s
🐧 Linux / Editor with ThreadSanitizer (target=editor, tests=yes, dev_build=yes, use_tsan=yes, use_llvm=yes, linker=lld)	27m 52s
🐧 Linux / Template w/ Mono (target=template_release)	23m 14s
🏁 Windows / Editor (target=editor, tests=yes)	41m 34s
🐧 Linux / Minimal template (target=template_release, everything disabled)	13m 42s
🏁 Windows / Template (target=template_release)	29m 46s
🪲 Godot CPP / Build and test Godot CPP	6m 43s
	5h 19m 40s

Provide feedback