OpenAI 403 workaround to merge approved PRs (microsoft#619)

### Motivation and Context

No PRs can be merged due to 403 on https://platform.openai.com

### Description

This is NOT a permanent fix as it does NOT address the root cause.
It is a temporary change so important PRs can be merged.

### Contribution Checklist

<!-- Before submitting this PR, please make sure: -->

- [ ] The code builds clean without any errors or warnings
- [ ] The PR follows the [Contribution
Guidelines](https://github.com/microsoft/chat-copilot/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/chat-copilot/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [ ] All unit tests pass, and I have added new tests where possible
- [ ] I didn't break anyone 😄

---------

Co-authored-by: Mollie Munoz <momuno@microsoft.com>

.github/workflows/markdown-link-check-config.json

@@ -23,17 +23,14 @@
     },
     {
       "pattern": "^https://localhost"
+    },
+    {
+      "pattern": "^https://platform.openai.com"
     }
   ],
   "timeout": "20s",
   "retryOn429": true,
   "retryCount": 3,
   "fallbackRetryDelay": "30s",
-  "aliveStatusCodes": [
-    200,
-    206,
-    429,
-    500,
-    503
-  ]
+  "aliveStatusCodes": [200, 206, 429, 500, 503]
 }