CI: Bump actions/cache to v4

Change-Id: I3be9e874235b51a1c83edcde71d3a9d74778b8bb
diff --git a/.github/workflows/ci_test.yml b/.github/workflows/ci_test.yml
index 4065798..b4b2c0d 100644
--- a/.github/workflows/ci_test.yml
+++ b/.github/workflows/ci_test.yml
@@ -59,7 +59,7 @@
         working-directory: ./KorAP-E2E-Tests
         run: npm ci
       - name: Setup cache for Chromium binary
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.cache/puppeteer/chrome
           key: ubuntu-latest-chromium-${{ hashFiles('packages/puppeteer-core/src/revisions.ts') }}