Bump langchain-openai from 0.3.7 to 0.3.28

---
updated-dependencies:
- dependency-name: langchain-openai
  dependency-version: 0.3.28
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

pyproject.toml

@@ -82,7 +82,7 @@ dependencies = [
     "langchain-milvus==0.1.8",
     "langchain-mistralai==0.2.7",
     "langchain-nvidia-ai-endpoints",
-    "langchain-openai==0.3.7",
+    "langchain-openai==0.3.28",
     "langchain==0.3.20",
     "langserve[all]==0.3.1",
     "markdownify==0.13.1",
@@ -115,7 +115,7 @@ rag = [
   "langchain-milvus==0.1.8",
   "langchain-mistralai==0.2.7",
   "langchain-nvidia-ai-endpoints",
-  "langchain-openai==0.3.7",
+  "langchain-openai==0.3.28",
   "langchain==0.3.20",
   "langdetect>=1.0.9",
   "langserve[all]==0.3.1",