Update version to 1.15.0 in google_gemini.py

Author: owndev

pipelines/google/google_gemini.py

@@ -4,7 +4,7 @@
 author_url: https://github.com/owndev/
 project_url: https://github.com/owndev/Open-WebUI-Functions
 funding_url: https://github.com/sponsors/owndev
-version: 1.14.1
+version: 1.15.0
 required_open_webui_version: 0.8.0
 license: Apache License 2.0
 description: Highly optimized Google Gemini pipeline with advanced image and video generation capabilities, intelligent compression, and streamlined processing workflows.