gnu: scotch: Update to 6.0.5a.

* gnu/packages/patches/pt-scotch-build-parallelism.patch: Delete files.
* gnu/packages/patches/scotch-build-parallelism.patch,
gnu/packages/patches/scotch-graph-diam-64.patch,
gnu/packages/patches/scotch-graph-induce-type-64.patch: New files.
* gnu/local.mk (dist_patch_DATA): Adjust accordingly.
* gnu/packages/maths.scm (scotch): Update to 6.0.5a.
[source](patches): Adjust accordingly.

gnu/packages/patches/scotch-build-parallelism.patch

@@ -0,0 +1,39 @@
+Fixes make with -j, otherwise scotch.h may not be generated by the time make
+tries to compile library_graph_diam.o et al.
+
+Reported upstream at
+https://gforge.inria.fr/tracker/index.php?func=detail&aid=21651&group_id=248&atid=1081
+
+diff --git a/src/libscotch/Makefile b/src/libscotch/Makefile
+index 9898894..b0ee14c 100644
+--- a/src/libscotch/Makefile
++++ b/src/libscotch/Makefile
+@@ -2229,6 +2229,28 @@ library_graph_color_f$(OBJ)	:	library_graph_color_f.c			\
+ 					common.h				\
+ 					scotch.h
+ 
++library_graph_diam$(OBJ)	:	library_graph_diam.c			\
++					module.h				\
++					common.h				\
++					graph.h					\
++					scotch.h
++
++library_graph_diam_f$(OBJ)	:	library_graph_diam.c			\
++					module.h				\
++					common.h				\
++					scotch.h
++
++library_graph_induce$(OBJ)	:	library_graph_diam.c			\
++					module.h				\
++					common.h				\
++					graph.h					\
++					scotch.h
++
++library_graph_induce_f$(OBJ)	:	library_graph_diam.c			\
++					module.h				\
++					common.h				\
++					scotch.h
++
+ library_graph_io_chac$(OBJ)	:	library_graph_io_chac.c			\
+ 					module.h				\
+ 					common.h				\