Clean up logic related to applying Gemini thought signatures to context messages

examples/foundational/49b-thinking-google.py

@@ -123,8 +123,9 @@ async def run_bot(transport: BaseTransport, runner_args: RunnerArguments):
                 "content": "Say hello briefly.",
             }
         )
-        # Here are some example prompts conducive to demonstrating
-        # thinking (picked from Google and Anthropic docs).
+        # Replace the above with one of these example prompts to demonstrate
+        # thinking.
+        # These examples come from Gemini and Anthropic docs.
         # messages.append(
         #     {
         #         "role": "user",

examples/foundational/49d-thinking-functions-google.py

@@ -149,8 +149,8 @@ async def run_bot(transport: BaseTransport, runner_args: RunnerArguments):
                 "content": "Say hello briefly.",
             }
         )
-        # Here is an example prompt conducive to demonstrating thinking and
-        # function calling.
+        # Replace the above with one of these example prompts to demonstrate
+        # thinking and function calling.
         # This example comes from Gemini docs.
         # messages.append(
         #     {