Bump Microsoft.NETFramework.ReferenceAssemblies and NServiceBus.Heartbeat

Bumps [Microsoft.NETFramework.ReferenceAssemblies](https://github.com/Microsoft/dotnet) and [NServiceBus.Heartbeat](https://github.com/Particular/NServiceBus.Heartbeat). These dependencies needed to be updated together.

Updates `Microsoft.NETFramework.ReferenceAssemblies` from 1.0.3 to 1.0.3
- [Commits](https://github.com/Microsoft/dotnet/commits)

Updates `NServiceBus.Heartbeat` from 3.0.1 to 4.0.1
- [Release notes](https://github.com/Particular/NServiceBus.Heartbeat/releases)
- [Commits](Particular/NServiceBus.Heartbeat@3.0.1...4.0.1)

---
updated-dependencies:
- dependency-name: Microsoft.NETFramework.ReferenceAssemblies
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: NServiceBus.Heartbeat
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

src/SmokeTest.Client/SmokeTest.Client.csproj

@@ -10,7 +10,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="NServiceBus.Heartbeat" Version="3.0.1" />
+    <PackageReference Include="NServiceBus.Heartbeat" Version="4.0.1" />
   </ItemGroup>
 
 </Project>

src/SmokeTest.Server/SmokeTest.Server.csproj

@@ -15,7 +15,7 @@
 
   <ItemGroup>
     <PackageReference Include="NServiceBus.CustomChecks" Version="3.0.1" />
-    <PackageReference Include="NServiceBus.Heartbeat" Version="3.0.1" />
+    <PackageReference Include="NServiceBus.Heartbeat" Version="4.0.1" />
   </ItemGroup>
 
 </Project>