Bump Microsoft.Health.Test.Utilities and NSubstitute

Bumps [Microsoft.Health.Test.Utilities](https://github.com/microsoft/healthcare-shared-components) and [NSubstitute](https://github.com/nsubstitute/NSubstitute). These dependencies needed to be updated together.

Updates `Microsoft.Health.Test.Utilities` from 9.0.10 to 9.1.18
- [Release notes](https://github.com/microsoft/healthcare-shared-components/releases)
- [Commits](microsoft/healthcare-shared-components@v9.0.10...v9.1.18)

Updates `NSubstitute` from 5.3.0 to 5.3.0
- [Release notes](https://github.com/nsubstitute/NSubstitute/releases)
- [Changelog](https://github.com/nsubstitute/NSubstitute/blob/main/CHANGELOG.md)
- [Commits](nsubstitute/NSubstitute@v5.3.0...v5.3.0)

---
updated-dependencies:
- dependency-name: Microsoft.Health.Test.Utilities
  dependency-version: 9.1.18
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: NSubstitute
  dependency-version: 5.3.0
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

Directory.Packages.props

@@ -1,7 +1,7 @@
 <Project>
   <!-- Shared dependencies versions.-->
   <PropertyGroup>
-    <HealthcareSharedPackageVersion>9.0.10</HealthcareSharedPackageVersion>
+    <HealthcareSharedPackageVersion>9.1.20</HealthcareSharedPackageVersion>
     <Hl7FhirVersion>5.11.4</Hl7FhirVersion>
     <Hl7FhirLegacyVersion>5.11.0</Hl7FhirLegacyVersion>
     <DotNetSdkPackageVersion>9.0.4</DotNetSdkPackageVersion>