break: bump the minimum required neovim version to 0.6 or higher (#1549)

So we can use `vim.json` and `vim.diagnostics`.

If you aren't able to update to 0.6.* yet you should pin the previous commit.

lua/telescope/builtin/internal.lua

@@ -245,7 +245,7 @@ internal.symbols = function(opts)
 
   local results = {}
   for _, source in ipairs(sources) do
-    local data = vim.fn.json_decode(Path:new(source):read())
+    local data = vim.json.decode(Path:new(source):read())
     for _, entry in ipairs(data) do
       table.insert(results, entry)
     end