Do not dehydrate data if CFG is enabled (#78546)

Two reasons:
1. CFG is already bigger because of all the extra checks. It's by design.
2. We might prefer to keep as many things readonly as possible.
3. This way at least some testing will run to ensure we didn't regress the non-dehydrated configuration.

src/coreclr/nativeaot/BuildIntegration/Microsoft.NETCore.Native.targets

@@ -214,7 +214,7 @@ The .NET Foundation licenses this file to you under the MIT license.
       <IlcArg Condition="$(IlcGenerateMetadataLog) == 'true'" Include="--metadatalog:$(NativeIntermediateOutputPath)%(ManagedBinary.Filename).metadata.csv" />
       <IlcArg Condition="$(TargetArchitecture) != ''" Include="--targetarch:$(TargetArchitecture)" />
       <IlcArg Condition="$(IlcMultiModule) == 'true'" Include="--multifile" />
-      <IlcArg Condition="$(IlcMultiModule) != 'true' and '$(IlcDehydrate)' != 'false'" Include="--dehydrate" />
+      <IlcArg Condition="$(IlcMultiModule) != 'true' and '$(IlcDehydrate)' != 'false' and '$(ControlFlowGuard)' != 'Guard'" Include="--dehydrate" />
       <IlcArg Condition="$(Optimize) == 'true'" Include="-O" />
       <IlcArg Condition="$(NativeDebugSymbols) == 'true'" Include="-g" />
       <IlcArg Condition="$(IlcDwarfVersion) == '5'" Include="--gdwarf-5" />