Revert "Merge pull request #318 from nickbabcock/dependabot/nuget/prometheus-net-7.0.0"

This reverts commit 26d87cf61cb19f7203be3a2e007e582e54aaf5fe, reversing
changes made to 363b3a499a488be1257134e1f50f39592b199805.

See #340

OhmGraphite/OhmGraphite.csproj

@@ -38,7 +38,7 @@
     <PackageReference Include="LibreHardwareMonitorLib" Version="0.9.2-pre186" />
     <PackageReference Include="InfluxDB.Client" Version="4.9.0" />
     <PackageReference Include="Npgsql" Version="7.0.0" />
-    <PackageReference Include="prometheus-net" Version="7.0.0" />
+    <PackageReference Include="prometheus-net" Version="6.0.0" />
     <PackageReference Include="System.Configuration.ConfigurationManager" Version="7.0.0" />
     <PackageReference Include="TopShelf" Version="4.3.0" />
     <PackageReference Include="Topshelf.NLog" Version="4.3.0" />