fix(ftplugin): source inherited Lua ftplugins

Problem:
Vimscript ftplugins that inherit a base ftplugin often use explicit
`runtime! ftplugin/foo.vim` patterns. This skips corresponding Lua
ftplugins, unlike top-level ftplugin loading.

Solution:
Use the existing `{vim,lua}` patterns for bang runtime imports while
preserving each call's current lookup breadth.

runtime/ftplugin/query.lua

@@ -13,7 +13,7 @@ vim.treesitter.start()
 -- set omnifunc
 vim.bo.omnifunc = 'v:lua.vim.treesitter.query.omnifunc'
 
-vim.opt_local.iskeyword:append('.')
+vim.api.nvim_set_option_value('iskeyword', '.', { scope = 'local', operation = 'append' })
 
 -- query linter
 local buf = vim.api.nvim_get_current_buf()