Bump Microsoft.Identity.Web from 2.13.3 to 2.13.4 in /webapi

Bumps [Microsoft.Identity.Web](https://github.com/AzureAD/microsoft-identity-web) from 2.13.3 to 2.13.4.
- [Release notes](https://github.com/AzureAD/microsoft-identity-web/releases)
- [Changelog](https://github.com/AzureAD/microsoft-identity-web/blob/master/changelog.md)
- [Commits](AzureAD/microsoft-identity-web@2.13.3...2.13.4)

---
updated-dependencies:
- dependency-name: Microsoft.Identity.Web
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

webapi/CopilotChatWebApi.csproj

@@ -24,7 +24,7 @@
     <PackageReference Include="Microsoft.SemanticKernel.Skills.Web" Version="0.21.230828.2-preview" />
     <PackageReference Include="Azure.Extensions.AspNetCore.Configuration.Secrets" Version="1.2.2" />
     <PackageReference Include="Microsoft.ApplicationInsights.AspNetCore" Version="2.21.0" />
-    <PackageReference Include="Microsoft.Identity.Web" Version="2.13.3" />
+    <PackageReference Include="Microsoft.Identity.Web" Version="2.13.4" />
     <PackageReference Include="PdfPig" Version="0.1.8" />
     <PackageReference Include="Swashbuckle.AspNetCore" Version="6.5.0" />
     <PackageReference Include="System.IdentityModel.Tokens.Jwt" Version="6.32.2" />