Add caching to `DisplayServer::can_create_rendering_device()` #40959

Job	Run time
📊 Static checks / Code style, file formatting, and docs	23s
🤖 Android / Editor (target=editor)	5m 24s
🍏 iOS / Template (target=template_release)	1m 58s
🤖 Android / Template arm32 (target=template_release, arch=arm32)	3m 24s
🌐 Web / Template w/ threads (target=template_release, threads=yes)	6m 14s
🤖 Android / Template arm64 (target=template_release, arch=arm64)	3m 3s
🐧 Linux / Editor w/ Mono (target=editor)	5m 57s
🌐 Web / Template w/o threads (target=template_release, threads=no)	7m 18s
🐧 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)	12m 4s
🐧 Linux / Editor with clang sanitizers (target=editor, tests=yes, dev_build=yes, use_asan=yes, use_ubsan=yes, use_llvm=yes, linker=lld)	8m 5s
🍎 macOS / Editor (target=editor, tests=yes)	4m 0s
🍎 macOS / Template (target=template_release, tests=yes)	3m 2s
🏁 Windows / Editor (target=editor, tests=yes)	8m 52s
🏁 Windows / Editor w/ clang-cl (target=editor, tests=yes, use_llvm=yes)	4m 20s
🐧 Linux / Editor with ThreadSanitizer (target=editor, tests=yes, dev_build=yes, use_tsan=yes, use_llvm=yes, linker=lld)	7m 8s
🏁 Windows / Template (target=template_release, tests=yes)	8m 31s
🐧 Linux / Template w/ Mono (target=template_release, tests=yes)	2m 56s
🐧 Linux / Minimal template (target=template_release, tests=yes, everything disabled)	2m 13s
🪲 Godot CPP / Build and test Godot CPP	8m 32s
	1h 43m 24s

Provide feedback