Updated OpenAI APIs to GA version 2024-02-01

[leongj]

Update the OpenAI API versions across:

• GPT chat model
• GPT vision model
• DALL-E model

Targeting the generally-available 2024-02-01 release. Includes updates across infra Bicep code, examples and docs.

Bugfix:

• Updated infra code to strip out - and _ from the environment name when creating the storage account name (alphanumeric only). Could've stripped out more characters, but these are the most common ones that people are using.

[davidxw]

This has been superseded by our recent update to GPT-4o (which also updated API versions)