nvim: lsp: Inlay hints API has changed

With the recent change to the API, without passing buffer number as
0 for the current buffer, inlay hints gets enabled for all buffers.

nvim/.config/nvim/lua/lsp.lua

@@ -16,7 +16,10 @@ local peek_definition = function()
 end
 
 local inlay_hint_toggle = function()
-  vim.lsp.inlay_hint.enable(not vim.lsp.inlay_hint.is_enabled())
+  local filter  = { bufnr = 0 }
+  local enabled = vim.lsp.inlay_hint.is_enabled(filter)
+
+  vim.lsp.inlay_hint.enable(not enabled, filter)
 end
 
 _G.InlayHintToggle = inlay_hint_toggle