Fix parenthesized detection for tuples (#6599)

## Summary

This PR fixes our code for detecting whether a tuple has its own
parentheses, which is necessary when attempting to preserve parentheses.
As-is, we were getting some cases wrong, like `(a := 1), (b := 3))` --
the detection code inferred that this _was_ parenthesized, and so
wrapped the entire thing in an unnecessary set of parentheses.

## Test Plan

`cargo test`

Before:

| project      | similarity index |
|--------------|------------------|
| cpython      | 0.75472          |
| django       | 0.99804          |
| transformers | 0.99618          |
| twine        | 0.99876          |
| typeshed     | 0.74288          |
| warehouse    | 0.99601          |
| zulip        | 0.99727          |

After:
| project      | similarity index |
|--------------|------------------|
| cpython      | 0.75473          |
| django       | 0.99804 |
| transformers | 0.99618          |
| twine        | 0.99876          |
| typeshed     | 0.74288          |
| warehouse    | 0.99601          |
| zulip        | 0.99727          |

crates/ruff_python_formatter/tests/snapshots/black_compatibility@py_39__pep_572_py39.py.snap

@@ -1,54 +0,0 @@
----
-source: crates/ruff_python_formatter/tests/fixtures.rs
-input_file: crates/ruff_python_formatter/resources/test/fixtures/black/py_39/pep_572_py39.py
----
-## Input
-
-```py
-# Unparenthesized walruses are now allowed in set literals & set comprehensions
-# since Python 3.9
-{x := 1, 2, 3}
-{x4 := x**5 for x in range(7)}
-# We better not remove the parentheses here (since it's a 3.10 feature)
-x[(a := 1)]
-x[(a := 1), (b := 3)]
-```
-
-## Black Differences
-
-```diff
---- Black
-+++ Ruff
-@@ -4,4 +4,4 @@
- {x4 := x**5 for x in range(7)}
- # We better not remove the parentheses here (since it's a 3.10 feature)
- x[(a := 1)]
--x[(a := 1), (b := 3)]
-+x[((a := 1), (b := 3))]
-```
-
-## Ruff Output
-
-```py
-# Unparenthesized walruses are now allowed in set literals & set comprehensions
-# since Python 3.9
-{x := 1, 2, 3}
-{x4 := x**5 for x in range(7)}
-# We better not remove the parentheses here (since it's a 3.10 feature)
-x[(a := 1)]
-x[((a := 1), (b := 3))]
-```
-
-## Black Output
-
-```py
-# Unparenthesized walruses are now allowed in set literals & set comprehensions
-# since Python 3.9
-{x := 1, 2, 3}
-{x4 := x**5 for x in range(7)}
-# We better not remove the parentheses here (since it's a 3.10 feature)
-x[(a := 1)]
-x[(a := 1), (b := 3)]
-```
-
-

crates/ruff_python_formatter/tests/snapshots/format@expression__tuple.py.snap

@@ -9,6 +9,8 @@ a1 = 1, 2
 a2 = (1, 2)
 a3 = (1, 2), 3
 a4 = ((1, 2), 3)
+a5 = (1), (2)
+a6 = ((1), (2))
 
 # Wrapping parentheses checks
 b1 = (("Michael", "Ende"), ("Der", "satanarchäolügenialkohöllische", "Wunschpunsch"), ("Beelzebub", "Irrwitzer"), ("Tyrannja", "Vamperl"),)
@@ -79,6 +81,8 @@ a1 = 1, 2
 a2 = (1, 2)
 a3 = (1, 2), 3
 a4 = ((1, 2), 3)
+a5 = (1), (2)
+a6 = ((1), (2))
 
 # Wrapping parentheses checks
 b1 = (

crates/ruff_python_formatter/tests/snapshots/format@statement__for.py.snap

@@ -38,6 +38,16 @@ for (x, y) in (z, w):
 # type comment
 for x in (): # type: int
     ...
+
+# Tuple parentheses for iterable.
+for x in 1, 2, 3:
+    pass
+
+for x in (1, 2, 3):
+    pass
+
+for x in 1, 2, 3,:
+    pass
 ```
 
 ## Output
@@ -76,6 +86,20 @@ for x, y in (z, w):
 # type comment
 for x in ():  # type: int
     ...
+
+# Tuple parentheses for iterable.
+for x in 1, 2, 3:
+    pass
+
+for x in (1, 2, 3):
+    pass
+
+for x in (
+    1,
+    2,
+    3,
+):
+    pass
 ```