gnu: zathura: Remove superfluous inputs from dependents.

* gnu/packages/pdf.scm (zathura-cb, zathura-ps, zathura-djvu,
zathura-pdf-mupdf)[inputs]: Remove GTK+, which is propagated from GIRARA.
(zathura-pdf-poppler): Likewise.  Remove CAIRO which is propagated from ZATHURA.

gnu/packages/pdf.scm

@@ -337,7 +337,6 @@ reading and editing of existing PDF files.")
     (native-inputs `(("pkg-config" ,pkg-config)))
     (propagated-inputs `(("girara" ,girara)))
     (inputs `(("libarchive" ,libarchive)
-              ("gtk+" ,gtk+)
               ("zathura" ,zathura)))
     (build-system gnu-build-system)
     (arguments
@@ -368,7 +367,6 @@ using libarchive.")
     (native-inputs `(("pkg-config" ,pkg-config)))
     (propagated-inputs `(("girara" ,girara)))
     (inputs `(("libspectre" ,libspectre)
-              ("gtk+" ,gtk+)
               ("zathura" ,zathura)))
     (build-system gnu-build-system)
     (arguments
@@ -400,7 +398,6 @@ using libspectre.")
     (propagated-inputs `(("girara" ,girara)))
     (inputs
      `(("djvulibre" ,djvulibre)
-       ("gtk+" ,gtk+)
        ("zathura" ,zathura)))
     (build-system gnu-build-system)
     (arguments
@@ -431,8 +428,7 @@ using the DjVuLibre library.")
     (native-inputs `(("pkg-config" ,pkg-config)))
     (propagated-inputs `(("girara" ,girara)))
     (inputs
-     `(("gtk+" ,gtk+)
-       ("jbig2dec" ,jbig2dec)
+     `(("jbig2dec" ,jbig2dec)
        ("libjpeg" ,libjpeg)
        ("mupdf" ,mupdf)
        ("openjpeg" ,openjpeg)
@@ -467,9 +463,7 @@ by using the @code{mupdf} rendering library.")
     (propagated-inputs `(("girara" ,girara)))
     (inputs
      `(("poppler" ,poppler)
-       ("gtk+" ,gtk+)
-       ("zathura" ,zathura)
-       ("cairo" ,cairo)))
+       ("zathura" ,zathura)))
     (build-system gnu-build-system)
     (arguments
      `(#:make-flags (list (string-append "PREFIX=" %output)