gnu: Drop gobject-introspection 1.73.1.

The actual gobject-introspection has been newer than its "next" variant for
some while.

* gnu/packages/glib.scm (gobject-introspection-next): Remove variable.
* gnu/packages/gtk.scm (gtksourceview)[native-inputs]: Replace
gobject-introspection-next with gobject-introspection.
* gnu/packages/guile-xyz.scm (guile-g-golf)[native-inputs]: Likewise.

gnu/packages/glib.scm

@@ -688,23 +688,6 @@ provide bindings to call into the C library.")
       ;; For tools.
       license:gpl2+))))
 
-(define-public gobject-introspection-next
-  (package
-    (inherit gobject-introspection)
-    (name "gobject-introspection")
-    (version "1.73.1")
-    (source (origin
-              (method url-fetch)
-              (uri (string-append "mirror://gnome/sources/"
-                                  "gobject-introspection/" (version-major+minor version)
-                                  "/gobject-introspection-" version ".tar.xz"))
-              (sha256
-               (base32 "1gkbx32as3v2286w7k3j24fwhkxj6brr49881m2zavxamfwxdm34"))
-              (patches (search-patches
-                        "gobject-introspection-cc-1.72.patch"
-                        "gobject-introspection-girepository.patch"
-                        "gobject-introspection-absolute-shlib-path-1.72.patch"))))))
-
 (define intltool
   (package
     (name "intltool")

gnu/packages/gtk.scm

@@ -652,7 +652,7 @@ printing and other features typical of a source code editor.")
      (list `(,glib "bin")               ; for glib-genmarshal, etc.
            gettext-minimal
            gi-docgen
-           gobject-introspection-next
+           gobject-introspection
            pkg-config
            vala
            ;; For testing.

gnu/packages/guile-xyz.scm

@@ -2517,7 +2517,7 @@ capabilities.")
            clutter
            xorg-server-for-tests))
     (propagated-inputs
-     (list gobject-introspection-next))
+     (list gobject-introspection))
     (home-page "https://www.gnu.org/software/g-golf/")
     (synopsis "Guile bindings for GObject Introspection")
     (description