Added changes made to OpenAiModel to release notes.

Author: n-o-u-r-h-a-n

docs/release_notes.md

@@ -25,6 +25,8 @@
     - `GPT_4` and `GPT_4_0613` are replaced by : `GPT_40`or `GPT_41`.
     - `CLAUDE_3_SONNET` is replaced by `CLAUDE_4_SONNET`.
     - `MIXTRAL_8X7B_INSTRUCT_V01` is replaced by `MISTRAL_SMALL_INSTRUCT`.
+- [OpenAI] Deprecated : `GPT_4`, `GPT_4_0613`.
+  - `GPT_4` and `GPT_4_0613` are replaced by : `GPT_40`or `GPT_41`.
 
 - [Prompt Registry] Resource group has been added as a optional parameter to all endpoints. Set it to `"default"` if it was not set before. Examples:
   - `client.importPromptTemplate(File)` --> `client.importPromptTemplate("default", File)`.