gnu: luminance-hdr: Replace dependency on QtWebKit with QtWebEngine.

See <https://issues.guix.gnu.org/53289> for more information about this change.

* gnu/packages/image-viewers.scm (luminance-hdr)[inputs]: Remove qtwebkit. Add
qtwebengine, qtdeclarative, and qtwebchannel.

gnu/packages/image-viewers.scm

@@ -607,7 +607,6 @@ It supports JPEG, PNG and GIF formats.")
      `(("qtbase" ,qtbase-5)
        ("qtdeclarative" ,qtdeclarative)
        ("qtsvg" ,qtsvg)
-       ("qtwebkit" ,qtwebkit)
        ("boost" ,boost)
        ("eigen" ,eigen)
        ;; ("gtest" ,gtest)
@@ -618,6 +617,9 @@ It supports JPEG, PNG and GIF formats.")
        ("libjpeg" ,libjpeg-turbo)
        ("lcms" ,lcms)
        ("openexr" ,openexr-2)
+       ("qtwebengine" ,qtwebengine)
+       ("qtdeclarative" ,qtdeclarative)
+       ("qtwebchannel" ,qtwebchannel)
        ("fftw" ,fftwf)
        ("gsl" ,gsl)
        ("libtiff" ,libtiff)))