feat: Make webpage summarization timeout configurable

[SyedaAnshrahGillani]

This commit introduces a configurable timeout for the webpage summarization process. Previously, the summarize_webpage function in utils.py had a hardcoded 60-second timeout. This change allows users to specify a custom timeout via the summarization_timeout field in the Configuration class, providing more flexibility for varying content lengths and network conditions.

• Added summarization_timeout field to Configuration in configuration.py.
• Modified summarize_webpage in utils.py to accept and use the new timeout.
• Updated tavily_search to pass the configurable timeout to summarize_webpage.