bug#73376: Treesitter does not rescan after indentation

[pranshu sharma <pranshusharma366@gmail.com>]

After indenting, treesitter does not rescan the region.  This causes
errors in the concrete syntax tree, which mess up indentation and syntax
colouring.

The issue I'm having is kind of hard to explain, but in a summary I have
the poorly indented code, where what's between '_'(which is not in the
code itself) is coloured:
---------------
f x =
               let _a_ = 2
                   _c_ = 1
  in a
--------------
Then when I indent it with haskell-ts-mode, I get:
---------------
f x =
  let _a_ = 2
      c = 1
  in a
--------------
When the 2 snippets of code have the exact same meaning.  If I revert
the buffer then the 'c' becomes coloured again.

This is not just problem with syntax highlighting, but if I was to
indent the 2nd snippet it would mess it up, as it has the wrong CST.