Update checkout action version in secretScan.yml

bumped from v4 to v6

Author: DChevrier1

.github/workflows/secretScan.yml

@@ -6,7 +6,7 @@ jobs:
   gitleaks:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: '0'
       - name: gitleaks-action