release: 2.8.1 (#510)

* fix(client): consider cognitiveservices.azure.com as azure (#470)

* Also consider cognitiveservices.azure.com an AzureEndpoint

Fixes https://github.com/openai/openai-java/issues/469

* Add comment regarding URL format

* release: 2.8.1

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Co-authored-by: Stefan Lobbenmeier <stefan.lobbenmeier@objego.de>
Co-authored-by: stainless-app[bot] <142633134+stainless-app[bot]@users.noreply.github.com>