tst_qimage: skip exifReadComments when the feature is not active

We need to skip the exifReadComments test case if reading text from
image has been configured off, like in webOS's Yocto recipe for QtBase.

Fixes: QTBUG-105393
Pick-to: 6.4
Change-Id: If45872ca7ed26620fa38bc6b47132363d661acdc
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>

tests/auto/gui/image/qimage/tst_qimage.cpp

@@ -3435,6 +3435,9 @@ void tst_QImage::exifInvalidData()
 
 void tst_QImage::exifReadComments()
 {
+#ifdef QT_NO_IMAGEIO_TEXT_LOADING
+    QSKIP("Reading text from image file is configured off");
+#endif
     QImage image;
     QVERIFY(image.load(m_prefix + "jpeg_exif_utf8_comment.jpg"));
     QVERIFY(!image.isNull());