[🪵] Update actions/cache action to v4.2.4

Author: renovate[bot]

.github/workflows/subsplit.yaml

@@ -22,7 +22,7 @@ jobs:
           user_email: '[email protected]'
       - name: Cache splitsh-lite
         id: splitsh-cache
-        uses: actions/cache@v4
+        uses: actions/cache@0400d5f644dc74513175e3cd8d07132dd4860809 # v4.2.4
         with:
           path: './.splitsh'
           key: '${{ runner.os }}-splitsh-d-101'