style: format code with Black and isort (#213)

This commit fixes the style issues introduced in 91c2416 according to the output
from Black and isort.

Details: None

Co-authored-by: deepsource-autofix[bot] <62050782+deepsource-autofix[bot]@users.noreply.github.com>
Co-authored-by: bartholomew-smith[bot] <156136305+bartholomew-smith[bot]@users.noreply.github.com>

githubapp/events/__init__.py

@@ -22,7 +22,7 @@ class instantiated with the event payload data.
     IssueCommentEditedEvent,
     IssueCommentEvent,
 )
-from .issues import IssueEditedEvent, IssueOpenedEvent, IssuesEvent, IssueClosedEvent
+from .issues import IssueClosedEvent, IssueEditedEvent, IssueOpenedEvent, IssuesEvent
 from .pull_request_review import (
     PullRequestReviewDismissedEvent,
     PullRequestReviewEditedEvent,