Bump System.Runtime.Caching from 6.0.0 to 7.0.0 in /src/Opserver.Core

Bumps [System.Runtime.Caching](https://github.com/dotnet/runtime) from 6.0.0 to 7.0.0.
- [Release notes](https://github.com/dotnet/runtime/releases)
- [Commits](dotnet/runtime@v6.0.0...v7.0.0)

---
updated-dependencies:
- dependency-name: System.Runtime.Caching
  dependency-type: direct:production
...

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

src/Opserver.Core/Opserver.Core.csproj

@@ -23,7 +23,7 @@
     <PackageReference Include="System.Data.SqlClient" Version="4.8.6" />
     <PackageReference Include="System.DirectoryServices" Version="6.0.0" />
     <PackageReference Include="System.Management" Version="6.0.0" />
-    <PackageReference Include="System.Runtime.Caching" Version="6.0.0" />
+    <PackageReference Include="System.Runtime.Caching" Version="7.0.0" />
   </ItemGroup>
   <ItemGroup>
     <Compile Update="Data\SQL\QueryPlans\ShowPlanXML.cs" SubType="Code" />