Bump Azure.Identity from 1.18.0 to 1.19.0 (#69)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

website/chatui/chatui.csproj

@@ -10,6 +10,6 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="Azure.AI.Projects" Version="1.2.0-beta.5" />
-    <PackageReference Include="Azure.Identity" Version="1.18.0" />
+    <PackageReference Include="Azure.Identity" Version="1.19.0" />
   </ItemGroup>
 </Project>