neovim requirement 0.7.0 -> 0.8.0, remove WinSeparator/VertSplit compatibility shims

lua/nvim-tree.lua

@@ -745,8 +745,8 @@ local function validate_options(conf)
 end
 
 function M.setup(conf)
-  if vim.fn.has "nvim-0.7" == 0 then
-    vim.notify_once("nvim-tree.lua requires Neovim 0.7 or higher", vim.log.levels.WARN)
+  if vim.fn.has "nvim-0.8" == 0 then
+    vim.notify_once("nvim-tree.lua requires Neovim 0.8 or higher", vim.log.levels.WARN)
     return
   end
 

lua/nvim-tree/colors.lua

@@ -69,8 +69,7 @@ local function get_links()
     CursorLineNr = "CursorLineNr",
     LineNr = "LineNr",
     CursorLine = "CursorLine",
-    VertSplit = "VertSplit",
-    WinSeparator = "NvimTreeVertSplit",
+    WinSeparator = "WinSeparator",
     CursorColumn = "CursorColumn",
     FileDirty = "NvimTreeGitDirty",
     FileNew = "NvimTreeGitNew",

lua/nvim-tree/view.lua

@@ -4,12 +4,6 @@ local events = require "nvim-tree.events"
 local utils = require "nvim-tree.utils"
 local log = require "nvim-tree.log"
 
-local function get_win_sep_hl()
-  -- #1221 WinSeparator not present in nvim 0.6.1 and some builds of 0.7.0
-  local has_win_sep = pcall(vim.cmd, "silent hi WinSeparator")
-  return has_win_sep and "WinSeparator:NvimTreeWinSeparator" or "VertSplit:NvimTreeWinSeparator"
-end
-
 M.View = {
   adaptive_size = false,
   centralize_selection = false,
@@ -38,7 +32,7 @@ M.View = {
       "CursorLine:NvimTreeCursorLine",
       "CursorLineNr:NvimTreeCursorLineNr",
       "LineNr:NvimTreeLineNr",
-      get_win_sep_hl(),
+      "WinSeparator:NvimTreeWinSeparator",
       "StatusLine:NvimTreeStatusLine",
       "StatusLineNC:NvimTreeStatuslineNC",
       "SignColumn:NvimTreeSignColumn",