gh-64502: Generate the option group flags in a stable order

They were emitted in the iteration order of a set of group identifiers.
The identifiers of the groups before the required parameters are small
negative integers, -1 and -2 have the same hash, so their order depended
on the size of Py_hash_t, and the code generated on a 32-bit platform
differed from the checked in one.

They are now emitted in the order of the parameters.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: serhiy-storchaka

Modules/clinic/_cursesmodule.c.h

@@ -356,7 +356,10 @@ def render_option_group_parsing(
 """)
                 continue
 
-            group_ids = {p.group for p in subset}  # eliminate duplicates
+            # Deduplicate the groups, but keep the order of parameters:
+            # the iteration order of a set of small negative integers
+            # depends on the platform.
+            group_ids = dict.fromkeys(p.group for p in subset)
             d: dict[str, str | int] = {}
             d['count'] = count
             d['name'] = f.name
@@ -371,7 +374,7 @@ def render_option_group_parsing(
                 p.converter.parse_argument(parse_arguments)
             d['parse_arguments'] = ", ".join(parse_arguments)
 
-            group_ids.discard(0)
+            group_ids.pop(0, None)
             lines = "\n".join([
                 self.group_to_variable_name(g) + " = 1;"
                 for g in group_ids