[LL] [cls] use stubBased symbol provider for builtins

this gives the following benefits:
1. no protobuf in memory, all data is already present in stubs
2. given that symbol provider for libraries is already stub based,
we can get rid of complicated code to find source psi by deserialized fir
3. it's also possible to reduce number of index access,
when fir is requested for given ktElement

analysis/analysis-api-standalone/analysis-api-standalone-base/src/org/jetbrains/kotlin/analysis/api/standalone/base/project/structure/StandaloneProjectFactory.kt

@@ -226,7 +226,7 @@ object StandaloneProjectFactory {
                     VirtualFileManager.getInstance().findFileByNioPath(path)
                 }
             }
-        }
+        }.distinct()
     }
 
     private fun withAllTransitiveDependencies(ktModules: List<KtModule>): List<KtModule> {