Restore type hints in MediaEntry to match last released version

Essentially, mark short_description as mandatory.
It, probably, should be optional, but I don't want to change the structure from what it was, at least for now.

Author: Electronic-Mango

src/simplejustwatchapi/query.py

@@ -361,7 +361,7 @@ class MediaEntry(NamedTuple):
     runtime_minutes: int
     """Runtime in minutes."""
 
-    short_description: str | None
+    short_description: str
     """Short description of this entry."""
 
     genres: list[str]

test/simplejustwatchapi/test_parser.py

@@ -343,6 +343,7 @@
         "originalReleaseYear": 2020,
         "originalReleaseDate": "12-02-2020",
         "runtime": 123,
+        "shortDescription": "Other description",
         "posterUrl": "/poster/url/3.jpg",
     },
 }
@@ -355,7 +356,7 @@
     2020,
     "12-02-2020",
     123,
-    None,
+    "Other description",
     [],
     None,
     None,