build(deps): Bump actions/checkout from 5 to 6 (#7)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ jobs:
         include:
           - os: ubuntu-24.04
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Build sourcemod plugin
         uses: maxime1907/action-sourceknight@v1
         with:
@@ -37,7 +37,7 @@ jobs:
     needs: build
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         if: github.ref == 'refs/heads/master' || github.ref == 'refs/heads/main'
 
       - uses: dev-drprasad/delete-tag-and-release@v1.1