Explicit sha

Author: dfed

.github/workflows/ci.yml

@@ -105,4 +105,4 @@ jobs:
           contents: read
         uses: actions/checkout@v4
       - name: Link Checker
-        uses: AlexanderDokuchaev/md-dead-link-check@v1.0.1
+        uses: AlexanderDokuchaev/md-dead-link-check@d5a37e0b14e5918605d22b34562532762ccb2e47 # v1.2.0