feat(client): improve error message for http timeouts

[jonathanblade]

Change Summary

Improve error message for http timeouts.

Closes https://github.com/RobertCraigie/prisma-client-py/issues/679.

Checklist

• [x] Unit tests for the changes exist
• [x] Tests pass without significant drop in coverage
• [ ] Documentation reflects changes where applicable
• [ ] Test snapshots have been updated if applicable

Agreement

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