Migrate from net-libs/webkit-gtk:4 to :4.1
Backported from emacs-29 branch
https://bugs.gentoo.org/893670

commit 7287b7b53a17f9b2d1b474466106806a9d57af47
Author: Ulrich Müller <ulm@gentoo.org>
Date:   Thu Feb 9 10:58:48 2023 +0100

    Support webkit2gtk-4.1

--- a/configure.ac
+++ b/configure.ac
@@ -2722,8 +2722,12 @@
     AC_MSG_ERROR([xwidgets requested but gtk3 not used.])
 
   WEBKIT_REQUIRED=2.12
-  WEBKIT_MODULES="webkit2gtk-4.0 >= $WEBKIT_REQUIRED"
+  WEBKIT_MODULES="webkit2gtk-4.1 >= $WEBKIT_REQUIRED"
   EMACS_CHECK_MODULES([WEBKIT], [$WEBKIT_MODULES])
+  if test "$HAVE_WEBKIT" = "no"; then
+    WEBKIT_MODULES="webkit2gtk-4.0 >= $WEBKIT_REQUIRED"
+    EMACS_CHECK_MODULES([WEBKIT], [$WEBKIT_MODULES])
+  fi
   HAVE_XWIDGETS=$HAVE_WEBKIT
   test $HAVE_XWIDGETS = yes ||
     AC_MSG_ERROR([xwidgets requested but WebKitGTK+ not found.])