build!: remove neovim qt

Neovim QT was originally bundled on Windows as a response to the then
lackluster terminal options. The situation has dramatically changed,
with viable options such as Windows terminal, Alacritty and Wezterm to
name a few. The Windows build no longer needs this special treatment for
neovim to be usable.

Pros:
  - Release builds will be smaller.
  - Less maintenance burden.
  - Clearer separation of responsibility (neovim issues go to the neovim
    repo and neovim-qt issues to the neovim-qt repo).
  - More consistent treatment between platforms.

Cons:
  - Users who've come to expect neovim-qt to be bundled with nvim will
    need to adjust and download neovim-qt from
    https://github.com/equalsraf/neovim-qt instead.
  - Similarly, build scripts will need to be adjusted to reflect this
    change.

Closes https://github.com/neovim/neovim/issues/21209.

src/nvim/CMakeLists.txt

@@ -703,59 +703,6 @@ if(WIN32)
       -P ${PROJECT_SOURCE_DIR}/cmake/WindowsDllCopy.cmake)
   add_dependencies(nvim_runtime_deps nvim_dll_deps)
 
-  if(USE_BUNDLED_NVIMQT)
-    set(NVIMQT_DEPS
-      # Dependencies for neovim-qt
-      bearer/qgenericbearer.dll
-      iconengines/qsvgicon.dll
-      imageformats/qgif.dll
-      imageformats/qicns.dll
-      imageformats/qico.dll
-      imageformats/qjpeg.dll
-      imageformats/qsvg.dll
-      imageformats/qtga.dll
-      imageformats/qtiff.dll
-      imageformats/qwbmp.dll
-      imageformats/qwebp.dll
-      platforms/qwindows.dll
-      styles/qwindowsvistastyle.dll
-      translations/qt_ar.qm
-      translations/qt_bg.qm
-      translations/qt_ca.qm
-      translations/qt_cs.qm
-      translations/qt_da.qm
-      translations/qt_de.qm
-      translations/qt_en.qm
-      translations/qt_es.qm
-      translations/qt_fi.qm
-      translations/qt_fr.qm
-      translations/qt_gd.qm
-      translations/qt_he.qm
-      translations/qt_hu.qm
-      translations/qt_it.qm
-      translations/qt_ja.qm
-      translations/qt_ko.qm
-      translations/qt_lv.qm
-      translations/qt_pl.qm
-      translations/qt_ru.qm
-      translations/qt_sk.qm
-      translations/qt_uk.qm
-      D3Dcompiler_47.dll
-      libEGL.dll
-      libgcc_s_seh-1.dll
-      libGLESv2.dll
-      libstdc++-6.dll
-      libwinpthread-1.dll
-      nvim-qt.exe
-      opengl32sw.dll
-      Qt5Core.dll
-      Qt5Gui.dll
-      Qt5Network.dll
-      Qt5Svg.dll
-      Qt5Widgets.dll
-      )
-  endif()
-
   # A CMake script is used for copying the files to avoid the
   # "command line is too long" error that occurs when Ninja tries running
   # a command that exceeds the length limit (8191 characters) on Windows.
@@ -766,9 +713,7 @@ if(WIN32)
       cat.exe
       tee.exe
       win32yank.exe
-      xxd.exe
-
-      ${NVIMQT_DEPS})
+      xxd.exe)
   get_filename_component(DEP_FILE_DIR ${DEP_FILE} DIRECTORY)
   set(EXTERNAL_BLOBS_SCRIPT "${EXTERNAL_BLOBS_SCRIPT}\n"
     "file(COPY \"${DEPS_PREFIX}/bin/${DEP_FILE}\"