build(deps): bump actions/cache from 3 to 4

Bumps [actions/cache](https://github.com/actions/cache) from 3 to 4.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v3...v4)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/ci-testing.yml

@@ -26,7 +26,7 @@ jobs:
         with:
           python-version: ${{ matrix.python-version }}
       #- name: Cache pip
-      #  uses: actions/cache@v3
+      #  uses: actions/cache@v4
       #  with:
       #    path: ~/.cache/pip
       #    key: ${{ runner.os }}-Benchmarks-${{ hashFiles('requirements.txt') }}
@@ -84,7 +84,7 @@ jobs:
         id: pip-cache
         run: echo "::set-output name=dir::$(pip cache dir)"
       - name: Cache pip
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ${{ steps.pip-cache.outputs.dir }}
           key: ${{ runner.os }}-${{ matrix.python-version }}-pip-${{ hashFiles('requirements.txt') }}