refactor(gepa): apply code cleanup principles consistently

- Use tuple syntax for startswith() (more Pythonic)
- Remove unnecessary try-except for JSON parsing (we control the source)

These follow the same principles applied in build_program refactor.

Author: Ju-usc

dspy/teleprompt/gepa/gepa_utils.py

@@ -161,7 +161,7 @@ def propose_component_texts(
             instruction_components = []
 
             for c in components_to_update:
-                if c.startswith(REACT_MODULE_PREFIX) or c.startswith(TOOL_MODULE_PREFIX):
+                if c.startswith((REACT_MODULE_PREFIX, TOOL_MODULE_PREFIX)):
                     tool_module_components.append(c)
                 else:
                     instruction_components.append(c)

dspy/teleprompt/gepa/instruction_proposal.py

@@ -383,11 +383,7 @@ def __call__(
                 continue
 
             # Deserialize module config
-            try:
-                current_module_config = json.loads(candidate[module_key])
-            except json.JSONDecodeError as e:
-                logger.error(f"Failed to deserialize config for {module_key}: {e}")
-                continue
+            current_module_config = json.loads(candidate[module_key])
 
             # Extract predictor keys (all keys except "tools")
             # Predictor keys are expected to be 1 for tool modules and 2 for ReAct modules (extra extract predictor)