Bedrock logs are not capturing trace info even when requests are blocked by the configured Guardrail.

I have enabled Bedrock Guardrails, but the expected trace data is missing from the Bedrock invocation logs upon a block intervention.
The implementation looks something like this:
```
guardrail_env['ANTHROPIC_CUSTOM_HEADERS'] = (
f'X-Amzn-Bedrock-GuardrailIdentifier: {guardrail_id}\n'
f'X-Amzn-Bedrock-GuardrailVersion: {guardrail_ver}\n'
'X-Amzn-Bedrock-Trace: ENABLED'
)

options = ClaudeAgentOptions(
model=model,
env={
**guardrail_env,
},
)
```