Fix pkg-config by removing duplicate "Requires" entry.

Index: src/lib/adwaita-qt.pc.cmake
--- src/lib/adwaita-qt.pc.cmake.orig
+++ src/lib/adwaita-qt.pc.cmake
@@ -5,8 +5,6 @@ includedir=@CMAKE_INSTALL_FULL_INCLUDEDIR@
 Name: adwaita-qt@ADWAITAQT_SUFFIX@
 Description: Qt Adwaita Style
 Version: @ADWAITAQT_VERSION@
-Requires: @PC_REQUIRES@
-@PC_REQUIRES_PRIVATE@
 
 Libs: -L${libdir} -ladwaitaqt@ADWAITAQT_SUFFIX@
 Cflags: -I${includedir}