gromacs: fix typo in pkgconfig-2025.patch

pkgs/applications/science/molecular-dynamics/gromacs/pkgconfig-2025.patch

···
 @@ -1,5 +1,4 @@
 -prefix=@CMAKE_INSTALL_PREFIX@
 -libdir=${prefix}/@CMAKE_INSTALL_LIBDIR@
-+libdir=@CMAKE_INSTALL_FULL_LIBDIR
- 
++libdir=@CMAKE_INSTALL_FULL_LIBDIR@
+
  Name: libgromacs@GMX_LIBS_SUFFIX@
  Description: Gromacs library