Added missing requirements to run the ./example/weather_agent.py

[VigneshHexo]

Updated requirements.txt: Added the missing libraries required to run the weather_agent.py script

• openmeteo_requests==1.2.0
• requests_cache==1.2.0
• retry_requests==2.0.0

[salesforce-cla[bot]]

Thanks for the contribution! Before we can merge this, we need @VigneshHexo to sign the Salesforce Inc. Contributor License Agreement.

[VigneshHexo]

These are not requirements for agentlite core code. We will label them as the example requirements

Agreed