[ScanDependencies] Fix a memory leak in dependency graph

Fix a memory leak from #75134.

(cherry picked from commit d8c3ebd)

Author: cachemeifyoucan

tools/libSwiftScan/libSwiftScan.cpp

@@ -37,6 +37,7 @@ void swiftscan_macro_dependency_dispose(
     swiftscan_string_dispose(macro->macro_dependencies[i]->executablePath);
     delete macro->macro_dependencies[i];
   }
+  delete[] macro->macro_dependencies;
   delete macro;
 }