Add [skip ci] and [ci skip] support to workflow

- Workflow now checks commit message for [skip ci] or [ci skip]
- If either flag is present, the entire workflow is skipped
- Allows developers to push changes without triggering CI when not needed

Usage:
  git commit -m "docs: update README [skip ci]"
  git commit -m "wip: work in progress [ci skip]"

Signed-off-by: Shreeya Patel <spatel@ciq.com>

Author: shreeya-patel98

.github/workflows/kernel-build-and-test-x86_64.yml

@@ -14,6 +14,7 @@ jobs:
   build:
     name: Build kernel
     runs-on: kernel-build
+    if: "!contains(github.event.head_commit.message, '[skip ci]') && !contains(github.event.head_commit.message, '[ci skip]')"
 
     steps:
     - name: Checkout kernel source