Remove unused references to System.ServiceModelHttp (#8496)

## Summary of changes

Removes unused references to
[System.ServiceModel.Http](https://www.nuget.org/packages/System.ServiceModel.Http)
package in the "dependencies" files

## Reason for change

As far as I can tell, we don't (and haven't ever) actually instrumented
this package. We only instrument the .NET Framework System.ServiceModel
library. Having the NuGet package is confusing and misleading (and means
we get dependabot alerts like [this
one](#8131)

## Implementation details

Remove the reference to the package

## Test coverage

Ran `GeneratePackageVersions` locally, and it looked fine

Author: andrewlock

tracer/build/_build/Honeypot/IntegrationGroups.cs

@@ -76,7 +76,7 @@ static IntegrationMap()
             NugetPackages.Add("System.Data.SQLite", new [] { "System.Data.SQLite" });
             NugetPackages.Add("StackExchange.Redis", new [] { "StackExchange.Redis" });
             NugetPackages.Add("StackExchange.Redis.StrongName", new [] { "StackExchange.Redis.StrongName" });
-            NugetPackages.Add("System.ServiceModel", new [] { "System.ServiceModel.Http" });
+            NugetPackages.Add("System.ServiceModel", new string[] { });
             NugetPackages.Add("System.Net.Requests", new [] { "System.Net.Requests" });
             NugetPackages.Add("xunit.execution.dotnet", new [] { "xunit.extensibility.execution" });
             NugetPackages.Add("xunit.execution.desktop", new [] { "xunit" });

tracer/build/supported_versions.json

@@ -1412,17 +1412,7 @@
     "assemblyName": "System.ServiceModel",
     "minAssemblyVersionInclusive": "4.0.0",
     "maxAssemblyVersionInclusive": "4.65535.65535",
-    "packages": [
-      {
-        "name": "System.ServiceModel.Http",
-        "minVersionAvailableInclusive": "3.9.0",
-        "minVersionSupportedInclusive": "4.0.0",
-        "minVersionTestedInclusive": null,
-        "maxVersionSupportedInclusive": "4.10.3",
-        "maxVersionAvailableInclusive": "10.0.652802",
-        "maxVersionTestedInclusive": null
-      }
-    ]
+    "packages": []
   },
   {
     "integrationName": "WebRequest",