message: [vcpkg portsdiff] Add missing const, remove unused #include
diff: #include "Paragraphs.h"
  #include "SortedVector.h"
  -#include "SourceParagraph.h"
  #include "vcpkg_Commands.h"
  #include "vcpkg_Maps.h"
  #include "vcpkg_System.h"
  @@ -139,8 +138,8 @@ namespace vcpkg::Commands::PortsDiff
  read_ports_from_commit(paths, git_commit_id_for_previous_snapshot);
  // Already sorted, so set_difference can work on std::vector too
  - std::vector<std::string> current_ports = Maps::extract_keys(current_names_and_versions);
  - std::vector<std::string> previous_ports = Maps::extract_keys(previous_names_and_versions);
  + const std::vector<std::string> current_ports = Maps::extract_keys(current_names_and_versions);
  + const std::vector<std::string> previous_ports = Maps::extract_keys(previous_names_and_versions);
  const SetElementPresence<std::string> setp =
  SetElementPresence<std::string>::create(current_ports, previous_ports);
  