Bump Microsoft.Identity.Web from 2.20.0 to 3.3.1 in /webapi

Bumps [Microsoft.Identity.Web](https://github.com/AzureAD/microsoft-identity-web) from 2.20.0 to 3.3.1.
- [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@2.20.0...3.3.1)

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

Signed-off-by: dependabot[bot] <[email protected]>

webapi/CopilotChatWebApi.csproj

@@ -22,7 +22,7 @@
     <PackageReference Include="Azure.Extensions.AspNetCore.Configuration.Secrets" Version="1.3.2" />
     <PackageReference Include="Microsoft.ApplicationInsights.AspNetCore" Version="2.22.0" />
     <PackageReference Include="Microsoft.Azure.Cosmos" Version="3.44.0" />
-    <PackageReference Include="Microsoft.Identity.Web" Version="2.20.0" />
+    <PackageReference Include="Microsoft.Identity.Web" Version="3.3.1" />
     <PackageReference Include="Microsoft.KernelMemory.Abstractions" Version="0.66.240709.1" />
     <PackageReference Include="Microsoft.SemanticKernel" Version="1.15.1" />
     <PackageReference Include="Microsoft.SemanticKernel.Abstractions" Version="1.15.1" />