chore(deps): update actions/checkout action to v6

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/linting-and-unit-testing.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5
+    - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
 
     - name: Use Node.js v24
       uses: actions/setup-node@v6