cmake: Use lld toolchain by default.

Author: xlauko

CMakePresets.json

@@ -11,6 +11,7 @@
             "displayName": "Ninja Multi-Config",
             "binaryDir": "${sourceDir}/builds/${presetName}",
             "generator": "Ninja Multi-Config",
+            "toolchainFile": "${sourceDir}/cmake/lld.toolchain.cmake",
             "cacheVariables": {
                 "CMAKE_CONFIGURATION_TYPES": "Release;RelWithDebInfo;Debug",
                 "VAST_ENABLE_TESTING": "ON",