Port from qAsConst() to std::as_const()

We've been requiring C++17 since Qt 6.0, and our qAsConst use finally
starts to bother us (QTBUG-99313), so time to port away from it
now.

Since qAsConst has exactly the same semantics as std::as_const (down
to rvalue treatment, constexpr'ness and noexcept'ness), there's really
nothing more to it than a global search-and-replace.

Task-number: QTBUG-99313
Change-Id: I88edd91395849574436299b8badda21bb93bea39
Reviewed-by: hjk <hjk@qt.io>

src/plugins/clangtools/documentquickfixfactory.cpp

@@ -56,7 +56,7 @@ void ClangToolQuickFixOperation::perform()
         refactoringFile->setChangeSet(changeSet);
     }
 
-    for (const TextEditor::RefactoringFilePtr &refactoringFile : qAsConst(refactoringFiles))
+    for (const TextEditor::RefactoringFilePtr &refactoringFile : std::as_const(refactoringFiles))
         refactoringFile->apply();
 }