Bump Microsoft.Extensions.Configuration.AzureKeyVault (#939)

Bumps [Microsoft.Extensions.Configuration.AzureKeyVault](https://github.com/aspnet/Extensions) from 3.1.17 to 3.1.18.
- [Release notes](https://github.com/aspnet/Extensions/releases)
- [Commits](https://github.com/aspnet/Extensions/commits)

---
updated-dependencies:
- dependency-name: Microsoft.Extensions.Configuration.AzureKeyVault
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

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

converter/dicom-cast/src/Microsoft.Health.DicomCast.Hosting/Microsoft.Health.DicomCast.Hosting.csproj

@@ -10,7 +10,7 @@
     <PackageReference Include="Microsoft.Azure.KeyVault" Version="2.3.2" />
     <PackageReference Include="Microsoft.Azure.Services.AppAuthentication" Version="1.6.1" />
     <PackageReference Include="Microsoft.Extensions.Configuration.Abstractions" Version="$(SdkPackageVersion)" />
-    <PackageReference Include="Microsoft.Extensions.Configuration.AzureKeyVault" Version="3.1.17" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.AzureKeyVault" Version="3.1.18" />
     <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="$(SdkPackageVersion)" />
     <PackageReference Include="Microsoft.Extensions.Hosting" Version="$(SdkPackageVersion)" />
     <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="$(SdkPackageVersion)" />