Don't set NUM_GLOBAL_PARTS for Zoltan (#392)

* Don't set NUM_GLOBAL_PARTS for Zoltan

Setting both NUM_GLOBAL_PARTS and NUM_LOCAL_PARTS together has issues

* Upgrade flake8 version used in precommit

Flake8 <6.1.0 and python 3.12 seems to have issues throwing up errors in
the middle of f-strings.

Fixed in 6.1.0: PyCQA/pycodestyle#1148

Upgrade to 6.1.0 only, as any newer versions introduce more errors that
either need fixing, or ignoring explicitly - which should probably be
done in a separate PR.

---------

Co-authored-by: Ben Fulton <bfulton@imperial.ac.uk>
Co-authored-by: Stephan Kramer <s.kramer@imperial.ac.uk>

Author: 3 people

.pre-commit-config.yaml

@@ -33,7 +33,7 @@ repos:
     hooks:
     -   id: pyupgrade
 -   repo: https://github.com/PyCQA/flake8
-    rev: 6.0.0
+    rev: 6.1.0
     hooks:
     -   id: flake8
         args: ["--max-line-length", "88", "--extend-ignore", "E203,E722"]

assemble/Zoltan_integration.F90

@@ -580,7 +580,6 @@ subroutine set_zoltan_parameters(final_adapt_iteration, flredecomp, target_procs
        else
           ierr = Zoltan_Set_Param(zz, "NUM_LOCAL_PARTS", "1"); assert(ierr == ZOLTAN_OK)
        end if
-       ierr = Zoltan_set_Param(zz, "NUM_GLOBAL_PARTS", int2str(target_procs)); assert(ierr == ZOLTAN_OK)
     end if
 
     if (.NOT. final_adapt_iteration) then
@@ -878,7 +877,9 @@ subroutine zoltan_load_balance(zz, changes, num_gid_entries, num_lid_entries, &
        ierr = Zoltan_LB_Partition(zz, changes, num_gid_entries, num_lid_entries, p1_num_import, p1_import_global_ids, &
           & p1_import_local_ids, p1_import_procs, import_to_part, p1_num_export, p1_export_global_ids,  &
           & p1_export_local_ids, p1_export_procs, export_to_part)
-       assert(ierr == ZOLTAN_OK)
+      if (ierr .ne. ZOLTAN_OK .and. ierr .ne. ZOLTAN_WARN) then
+         FLAbort("Zoltan_LB_Partition failed in zoltan_load_balance.")
+      end if
 
        ! calculate how many owned nodes we'd have after doing the planned load balancing
        num_nodes_after_balance = num_nodes + p1_num_import - p1_num_export