refactor: remove unnecessary parentheses after keyword (#39)

Extra parentheses in code can be removed for improved readability.  In the examples below, the first example is more readable than the second one.

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

src/plugins/nonebot_plugin_githubcard/__init__.py

@@ -28,6 +28,6 @@ def match_link_parts(link):
 async def github_handle(bot: Bot, event: GroupMessageEvent, state: T_State):
     url = match_link_parts(event.get_plaintext())
     imageUrl = await get_github_reposity_information(url)
-    if (imageUrl == "获取信息失败"):
+    if imageUrl == "获取信息失败":
         raise AssertionError
     await github.send(MessageSegment.image(imageUrl))