cmGlobalVisualStudio7Generator: Drop unused method

Since commit f47b4f68a9 (Drop Visual Studio 7 generator for VS .NET
2002, 2016-03-10, v3.6.0-rc1~268^2), the `WriteTargetDepends` method has
not been used.

Source/cmGlobalVisualStudio7Generator.cxx

@@ -458,22 +458,6 @@ void cmGlobalVisualStudio7Generator::WriteTargetsToSolution(
   }
 }
 
-void cmGlobalVisualStudio7Generator::WriteTargetDepends(
-  std::ostream& fout, OrderedTargetDependSet const& projectTargets)
-{
-  for (cmGeneratorTarget const* target : projectTargets) {
-    if (!target->IsInBuildSystem()) {
-      continue;
-    }
-    cmValue vcprojName = target->GetProperty("GENERATOR_FILE_NAME");
-    if (vcprojName) {
-      std::string dir =
-        target->GetLocalGenerator()->GetCurrentSourceDirectory();
-      this->WriteProjectDepends(fout, *vcprojName, dir, target);
-    }
-  }
-}
-
 void cmGlobalVisualStudio7Generator::WriteFolders(std::ostream& fout)
 {
   cm::string_view const prefix = "CMAKE_FOLDER_GUID_";

Source/cmGlobalVisualStudio7Generator.h

@@ -148,8 +148,6 @@ protected:
   virtual void WriteTargetsToSolution(
     std::ostream& fout, cmLocalGenerator* root,
     OrderedTargetDependSet const& projectTargets);
-  virtual void WriteTargetDepends(
-    std::ostream& fout, OrderedTargetDependSet const& projectTargets);
   virtual void WriteTargetConfigurations(
     std::ostream& fout, std::vector<std::string> const& configs,
     OrderedTargetDependSet const& projectTargets);