feat(integration-service): added env file to load the API_KEYS for various integrations

[Vedantsahai18]

[!IMPORTANT] Add environment variable handling for API keys in integration services using environs.

• Environment Variables:
  • Add env.py to load API keys and other sensitive data using environs.
  • Update docker-compose.yml to include new environment variables for integrations.
• Integration Updates:
  • Modify brave.py, browserbase.py, cloudinary.py, email.py, llama_parse.py, spider.py, and weather.py to use environment variables for API keys.
  • Replace hardcoded 'DEMO_API_KEY' and similar placeholders with actual environment variables.
• Dependencies:
  • Add environs to pyproject.toml for environment variable management.

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