language: Improve auto-indentation when using round brackets in Python (#31260)

Follow-up to #29625 and #30902

This PR reintroduces auto-intents for brackets in Python and fixes some
cases where an indentation would be triggered if it should not. For
example, upon typing

```python
a = []
```
and inserting a newline after, the next line would be indented although
it shoud not be.

Bracket auto-indentation was tested prior to #29625 but removed there
and the test updated accordingly. #30902 reintroduced this for all
brackets but `()`. I reintroduced this here, reverted the changes to the
test so that indents also happen after typing `()`. This is frequently
used for tuples and multiline statements in Python.

Release Notes:

- Improved auto-indentation when using round brackets in Python.

crates/languages/src/python.rs

@@ -1236,12 +1236,12 @@ mod tests {
                 "def a():\n  \n  if a:\n    b()\n  else:\n    "
             );
 
-            // indent after an open paren. the closing  paren is not indented
+            // indent after an open paren. the closing paren is not indented
             // because there is another token before it on the same line.
             append(&mut buffer, "foo(\n1)", cx);
             assert_eq!(
                 buffer.text(),
-                "def a():\n  \n  if a:\n    b()\n  else:\n    foo(\n    1)"
+                "def a():\n  \n  if a:\n    b()\n  else:\n    foo(\n      1)"
             );
 
             // dedent the closing paren if it is shifted to the beginning of the line

crates/languages/src/python/indents.scm

@@ -1,3 +1,4 @@
+(_ "(" ")" @end) @indent
 (_ "[" "]" @end) @indent
 (_ "{" "}" @end) @indent