check_kernel_commits.py: Ruff formatting

This was done automatically by ruff format. Default configuration is used.

Variable l was replaced by index due to #E741. It is not recommened
to use variables named 'I', 'O' or 'l' because they are hard to read.

Signed-off-by: Roxana Nicolescu <rnicolescu@ciq.com>

Author: roxanan1996

.pre-commit-config.yaml

@@ -12,7 +12,6 @@ repos:
 exclude: |
   (?x)^(
   ciq-cherry-pick.py |
-  check_kernel_commits.py |
   ciq_helpers.py |
   jira_pr_check.py |
   release_config.py |