Manually inline _locally_permitted_modifiers

See semgrep/ocaml-tree-sitter-semgrep#286

When generating a simplified grammar, the `ocaml-tree-sitter` code
generator forces all hidden nodes to be visible. It appears that hidden
nodes automatically get marked as `inline`, and that without that
auto-inlining, the `_locally_permitted_modifiers` rule causes a
conflict.

Rather than making the semgrep folks work around their conflict, we just
check the `inline` declaration into the grammar itself so that it sticks
around in the simplified grammar.

grammar.js

@@ -214,6 +214,7 @@ module.exports = grammar({
     $._as_bang_custom,
     $._async_keyword_custom,
   ],
+  inline: ($) => [$._locally_permitted_modifiers],
   rules: {
     ////////////////////////////////
     // File Structure