Bump Hl7.Fhir.R4 from 5.12.2 to 6.0.1

---
updated-dependencies:
- dependency-name: Hl7.Fhir.R4
  dependency-version: 6.0.1
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

src/Spark.Engine/Spark.Engine.csproj

@@ -15,7 +15,7 @@
 
     <ItemGroup>
         <PackageReference Include="Fhir.Metrics" Version="1.3.1" />
-        <PackageReference Include="Hl7.Fhir.R4" Version="5.12.2" />
+        <PackageReference Include="Hl7.Fhir.R4" Version="6.0.1" />
     </ItemGroup>
 
 </Project>