Update actions/cache digest to 6849a64

Author: renovate[bot]

.github/workflows/ci.yml

@@ -18,7 +18,7 @@ jobs:
           version-type: strict
 
       - name: Restore the deps and _build cache
-        uses: actions/cache@3624ceb22c1c5a301c8db4169662070a689d9ea8 # v4
+        uses: actions/cache@6849a6489940f00c2f30c0fb92c6274307ccb58a # v4
         id: restore-cache
         env:
           OTP_VERSION: ${{ steps.beam.outputs.otp-version }}