bump actions/cache from 1 to 4 (#24)

Author: dependabot[bot]

.github/workflows/UnitTest.yml

@@ -38,7 +38,7 @@ jobs:
         with:
           version: ${{ matrix.julia-version }}
           arch: ${{ matrix.julia-arch }}
-      - uses: actions/cache@v1
+      - uses: actions/cache@v4
         env:
           cache-name: cache-artifacts
         with: