update tree-sitter-elixir

The new revision handles a case that I come across often: a stab
clause (i.e. '->') with an empty right hand side:

    Enum.map(xs, fn x ->
    end)

The old version would parse the "end" token as an error.

This is technically valid syntax but more importantly it comes up
very often when editing, and the old revision would flicker between
the keyword highlight and the warning highlight.

languages.toml

@@ -91,7 +91,7 @@ indent = { tab-width = 2, unit = "  " }
 
 [[grammar]]
 name = "elixir"
-source = { git = "https://github.com/elixir-lang/tree-sitter-elixir", rev = "60863fc6e27d60cf4b1917499ed2259f92c7800e"  }
+source = { git = "https://github.com/elixir-lang/tree-sitter-elixir", rev = "1dabc1c790e07115175057863808085ea60dd08a"  }
 
 [[language]]
 name = "fish"