Remove duplicate OpenMeteo tool and move to Bridge structure

The OpenMeteo tool was duplicated in both Toolbox/Tool and Bridge/OpenMeteo
directories. This commit removes the duplicate and ensures everything uses
the Bridge structure.

Changes:
- Remove src/agent/src/Toolbox/Tool/OpenMeteo.php
- Move tests from tests/Toolbox/Tool to tests/Bridge/OpenMeteo
- Move fixtures from fixtures/Tool to fixtures/Bridge/OpenMeteo
- Rename fixture files from openmeteo-*.json to *.json
- Update test to use Bridge namespace and new fixture paths

Author: OskarStark