Fix clang build error.

Re #18366

Framework/DataObjects/test/PeakColumnTest.h

@@ -120,7 +120,7 @@ public:
   void test_read_locale_awerness() {
     const std::vector<std::string> columnNames{"h", "k", "l", "RunNumber"};
     const std::vector<double> columnValues{-2.0, 5.0, 12.0, 143290.0};
-    const TestingNumpunctFacet numpunct;
+    TestingNumpunctFacet numpunct;
     const std::locale testLocale(std::locale::classic(), &numpunct);
     for (size_t i = 0; i < columnNames.size(); ++i) {
       PeakColumn pc(m_peaks, columnNames[i]);