fix(google_gemini.py): increment version to 1.8.1

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: 1.8.0
+version: 1.8.1
 required_open_webui_version: 0.6.26
 license: Apache License 2.0
 description: Highly optimized Google Gemini pipeline with advanced image generation capabilities, intelligent compression, and streamlined processing workflows.