Config fixes

Author: klieret

configs/pvp/default_vs_more_prescriptive/gpt-5/battlesnake.yaml

@@ -20,8 +20,6 @@ players:
       agent: !include mini/more_prescriptive.yaml
       model:
         model_name: openai/gpt-5
-  - agent: dummy
-    name: dummy
 prompts:
   game_description: |
     You are a software developer ({{player_id}}) competing in a coding game called BattleSnake.

configs/pvp/default_vs_more_prescriptive/gpt-5/robotrumble.yaml

@@ -15,7 +15,7 @@ players:
     config:
       agent: !include mini/more_prescriptive.yaml
       model:
-        model_name: openai/gpt-5-mini
+        model_name: openai/gpt-5
 prompts:
   game_description: |
     You are a software developer ({{player_id}}) competing in a coding game called RobotRumble.

configs/pvp/default_vs_more_prescriptive/sonnet-4/battlesnake.yaml

@@ -20,8 +20,6 @@ players:
       agent: !include mini/more_prescriptive.yaml
       model:
         model_name: anthropic/claude-sonnet-4-20250514
-  - agent: dummy
-    name: dummy
 prompts:
   game_description: |
     You are a software developer ({{player_id}}) competing in a coding game called BattleSnake.