fix SyntaxWarning in pipes.py docstring for Python 3.12 [DAT-817]

[ackdav]

Summary

Converts the get_information docstring in verdin/api/pipes.py to a raw string (r"""...""") to suppress a SyntaxWarning: invalid escape sequence '\.' raised by Python 3.12+.

Surfaced during DAT-815 integration test run.

Risks & Validation

No behavioural change.

Warning observed in DAT-815 CI run:

=============================== warnings summary ===============================
.venv/lib/python3.12/site-packages/verdin/api/pipes.py:295
  /home/runner/work/analytics-backend/analytics-backend/.venv/lib/python3.12/site-packages/verdin/api/pipes.py:295: SyntaxWarning: invalid escape sequence '\.'
    See: https://www.tinybird.co/docs/api-reference/pipe-api#get--v0-pipes-(.+\.pipe)

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
==================================== PASSES ====================================
=================== 9 passed, 1 warning in 110.61s (0:01:50) ===================

[thrau]

LGTM thanks! escaping the . would probably also have been an option? but this is fine :-)