Bump actions/cache from 3 to 4 (#18)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/build.yml

@@ -38,7 +38,7 @@ jobs:
         run: echo "::set-output name=dir::$(composer config cache-files-dir)"
 
       - name: Cache dependencies
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ${{ steps.composer-cache.outputs.dir }}
           key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}