fix(treesitter): really backup spelloptions (#22145)

see 0887ad1cbb for the original commit on
master, and 80bbba94d6 for the backport on
the branch, which forgot to backup the original setting value.

CMakeLists.txt

@@ -133,8 +133,8 @@ endif()
 # version string, else they are combined with the result of `git describe`.
 set(NVIM_VERSION_MAJOR 0)
 set(NVIM_VERSION_MINOR 8)
-set(NVIM_VERSION_PATCH 3)
-set(NVIM_VERSION_PRERELEASE "") # for package maintainers
+set(NVIM_VERSION_PATCH 4)
+set(NVIM_VERSION_PRERELEASE "-dev") # for package maintainers
 
 # API level
 set(NVIM_API_LEVEL 10)         # Bump this after any API change.

runtime/lua/vim/treesitter/highlighter.lua

@@ -88,6 +88,8 @@ function TSHighlighter.new(tree, opts)
     end
   end
 
+  self.orig_spelloptions = vim.bo[self.bufnr].spelloptions
+
   vim.bo[self.bufnr].syntax = ''
   vim.b[self.bufnr].ts_highlight = true