Bump actions/cache from 2 to 4

Bumps [actions/cache](https://github.com/actions/cache) from 2 to 4.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v2...v4)

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

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

Author: dependabot[bot]

.github/workflows/benchmarks.yml

@@ -63,7 +63,7 @@ jobs:
         path: cbdr
 
     - name: retrieve cache cbdr
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: |
           ~/.cargo/bin/
@@ -78,15 +78,15 @@ jobs:
         key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
 
     - name: retrieve cache main
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: |
           ${{github.workspace}}/main/
         key: ${{ runner.os }}-gwb-main-v3}}
 
 
     - name: retrieve cache feature
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: |
           ${{github.workspace}}/feature/