phonon/phonon-backend-vlc: update

[Johnnynator]

• phonon-qt5: update to 4.12.0.
• phonon-qt5-backend-vlc: update to 0.12.0.

[github-actions]

Pull Requests become stale 90 days after last activity and are closed 14 days after that. If this pull request is still relevant bump it or assign it.

[Luciogi]

This would build both qt5,6 versions

diff --git a/srcpkgs/phonon/template b/srcpkgs/phonon/template
index ff0883ce588..4c20061710a 100644
--- a/srcpkgs/phonon/template
+++ b/srcpkgs/phonon/template
@@ -3,7 +3,7 @@ pkgname=phonon
 version=4.12.0
 revision=1
 build_style=cmake
-configure_args="-DPHONON_BUILD_PHONON4QT5=ON -DPHONON_INSTALL_QT_EXTENSIONS_INTO_SYSTEM_QT=ON"
+configure_args="-DPHONON_INSTALL_QT_EXTENSIONS_INTO_SYSTEM_QT=ON"
 hostmakedepends="extra-cmake-modules qt5-host-tools qt5-devel
  qt6-base qt6-tools qt6-tools"
 makedepends="glib-devel qt5-devel qt5-tools-devel pulseaudio-devel

Everything is fine except short_desc

[Johnnynator]

Added some short_descs and moved the designer plugins into the -devel packages.