Update workhorse timeout to 55s

What does this MR do and why?

This MR changes the timeout settings of Workhorse for Code Generation requests from 30s to 55s

• Related to gitlab-org/modelops/applied-ml/code-suggestions/ai-assist!625 (closed)
• For Align timeout settings of Code Generation request (#436430 - closed)

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Related to Align timeout settings of Code Generation request (#436430 - closed)