ClangFormat: Move tests into plugin

That's where they belong

Change-Id: I78e33e76a2f42f05961f6fab31da5f3dd583a2e9
Reviewed-by: Artem Sokolovskii <artem.sokolovskii@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/clangformat/clangformatplugin.cpp

@@ -29,6 +29,7 @@
 #include "clangformatconstants.h"
 #include "clangformatindenter.h"
 #include "clangformatutils.h"
+#include "tests/clangformat-test.h"
 
 #include <utils/qtcassert.h>
 
@@ -160,4 +161,13 @@ bool ClangFormatPlugin::initialize(const QStringList &arguments, QString *errorS
     return true;
 }
 
+QVector<QObject *> ClangFormatPlugin::createTestObjects() const
+{
+    return {
+#ifdef WITH_TESTS
+        new Internal::ClangFormatTest,
+#endif
+    };
+}
+
 } // namespace ClangFormat