Enum.value inferred as tuple[Literal[..]]

Enum value with a trailing comma is reported as a 1-tuple, but it's str and runtime.

```python
class BodyType1(str, Enum):
Text = "text",
Html = "html",

class BodyType2(str, Enum):
Text = "text"
Html = "html"

body_type_1: str = BodyType1.Text.value
body_type_2: str = BodyType2.Text.value

print(type(body_type_1))
print(type(body_type_2))
```
The BodyType example is taken from Graph SDK https://github.com/microsoftgraph/msgraph-sdk-python/blob/main/msgraph/generated/models/body_type.py
To my knowledge values separated with comma will all be passed to __init__ (https://docs.python.org/3/library/enum.html#enum.Enum.__init__).
Here `Text = "text",` should be equivalent to `str("text",)`.

```
$ pyright --version
pyright 1.1.408

$ pyright test.py
error: Type "tuple[Literal['text']]" is not assignable to declared type "str"
"tuple[Literal['text']]" is not assignable to "str" (reportAssignmentType)

$ python --version
Python 3.13.7

$ python test.py

```

Start with the minimal Enum reproducer in the issue and compare Pyright's inferred type with Python's Enum documentation on tuple values and __init__. Done means both trailing-comma and non-comma enum values are accepted as str where runtime behavior confirms that type, with regression coverage added in the relevant Pyright tests.

Written by the indexing model from the issue text.