tree-sitter: ignore matches in inner scopes

Previously, placing the cursor on line 1 would highlight every elif and
else in the whole block of code. % would jump to line 4, then % from
there would cycle between lines 2, 4 and 6.

 1   if noice:
 2       if yeah:
 3           pass
 4       elif no:
 5           pass
 6       else:
 7           pass
 8   elif blah:
 9       pass
10   else:
11       pass

With the change, which I think the code had contemplated given there was
already an unused `M.containing_scope(node, bufnr, info.key)` call, % will
only move between ifs and elses that are in the same `@scope.if_`, and
not to any inner scopes. Hence the example will have two mutually
exclusive %-cycles: [1, 8, 10] and [2, 4, 6].

lua/treesitter-matchup/internal.lua

@@ -248,13 +248,14 @@ function M.get_matching(delim, down, bufnr)
           and (row >= info.search_range[1]
             and row <= info.search_range[3]) then
 
-        local scope = M.containing_scope(node, bufnr, info.key)
+        local target_scope = M.containing_scope(node, bufnr, info.key)
+        if info.scope == target_scope then
+          local text = ts_utils.get_node_text(node, bufnr)[1]
+          table.insert(matches, {text, row + 1, col + 1})
 
-        local text = ts_utils.get_node_text(node, bufnr)[1]
-        table.insert(matches, {text, row + 1, col + 1})
-
-        if side == 'close' then
-          got_close = true
+          if side == 'close' then
+            got_close = true
+          end
         end
       end
     end