v0.7.8

Changed underlying openai/client package version from 0.7.5 to 0.7.8 containing the following updates:

What's New

• Add support for GTP-4 vision on the chat completion endpoint by @gehrisandro in openai-php/client#241
• Add support for tool calls on the chat completion endpoint by @gehrisandro in openai-php/client#239
• Add support for the audio speech endpoint by @gehrisandro in openai-php/client#237

Full Changelog: v0.7.5...v0.7.8