ci: bump cache version

Author: fjebaker

.github/workflows/auto-register.yml

@@ -28,7 +28,7 @@ jobs:
       - uses: julia-actions/setup-julia@v1
         with:
           version: ${{ matrix.julia-version }}
-      - uses: actions/cache@v1
+      - uses: actions/cache@v4
         env:
           cache-name: cache-artifacts
         with: