refactor: refactor unnecessary else / elif when if block has a …

…`return` statement (#35)

The use of `else` or `elif` becomes redundant and can be dropped if the last statement under the leading `if` / `elif` block is a `return` statement.
In the case of an `elif` after `return`, it can be written as a separate `if` block.
For `else` blocks after `return`, the statements can be shifted out of `else`. Please refer to the examples below for reference.

Refactoring the code this way can improve code-readability and make it easier to maintain.

Co-authored-by: deepsource-autofix[bot] <62050782+deepsource-autofix[bot]@users.noreply.github.com>

src/plugins/ncm/__init__.py

@@ -41,7 +41,7 @@ async def song_is_open(event: Union[GroupMessageEvent, PrivateMessageEvent]) ->
         setting.insert({"group_id": event.group_id,
                        "song": False, "list": False})
         return False
-    elif isinstance(event, PrivateMessageEvent):
+    if isinstance(event, PrivateMessageEvent):
         if info := setting.search(Q["user_id"] == event.user_id):
             return info[0]["song"]
         setting.insert({"user_id": event.user_id, "song": True, "list": True})
@@ -55,27 +55,24 @@ async def playlist_is_open(
         info = setting.search(Q["group_id"] == event.group_id)
         if info:
             return info[0]["list"]
-        else:
-            setting.insert({"group_id": event.group_id,
-                           "song": False, "list": False})
-            return False
+        setting.insert({"group_id": event.group_id,
+                       "song": False, "list": False})
+        return False
     elif isinstance(event, PrivateMessageEvent):
         info = setting.search(Q["user_id"] == event.user_id)
         if info:
             return info[0]["list"]
-        else:
-            setting.insert({"user_id": event.user_id,
-                           "song": True, "list": True})
-            return True
+        setting.insert({"user_id": event.user_id,
+                       "song": True, "list": True})
+        return True
 
 
 async def check_search() -> bool:
     info = setting.search(Q["global"] == "search")
     if info:
         return info[0]["value"]
-    else:
-        setting.insert({"global": "search", "value": True})
-        return True
+    setting.insert({"global": "search", "value": True})
+    return True
 
 
 async def music_set_rule(event: Union[GroupMessageEvent, PrivateMessageEvent]) -> bool: