[Integration][Gitlab] Use Fastapi background tasks in gitlab webhooks

[omby8888]

…delay in response

Description

What - Use Fastapi background tasks in gitlab webhooks Why - To avoid gitlab's 10 sec timeout on webhooks responses

Type of change

Please leave one option from the following and delete the rest:

• [X] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] New Integration (non-breaking change which adds a new integration)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] Non-breaking change (fix of existing functionality that will not change current behavior)
• [ ] Documentation (added/updated documentation)

Screenshots

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API Documentation

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