[StepSecurity] ci: Harden GitHub Actions (#9825)

Signed-off-by: StepSecurity Bot <bot@stepsecurity.io>

Author: step-security-bot

.github/workflows/maintenance-check-kernel-security.yml

@@ -33,7 +33,7 @@ jobs:
           egress-policy: audit
 
       - name: Checkout repository
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
           fetch-depth: 0
 
@@ -42,7 +42,7 @@ jobs:
         uses: tj-actions/changed-files@9426d40962ed5378910ee2e21d5f8c6fcbf2dd96 # v46.0.5
 
       - name: Checkout repository
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
           repository: a13xp0p0v/kconfig-hardened-check
           path: kconfig-hardened-check