Bump eth-pkg/apt-deb-cache from 0.2.5 to 0.2.6

Bumps [eth-pkg/apt-deb-cache](https://github.com/eth-pkg/apt-deb-cache) from 0.2.5 to 0.2.6.
- [Release notes](https://github.com/eth-pkg/apt-deb-cache/releases)
- [Commits](eth-pkg/apt-deb-cache@v0.2.5...v0.2.6)

---
updated-dependencies:
- dependency-name: eth-pkg/apt-deb-cache
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

action.yml

@@ -45,7 +45,7 @@ runs:
       shell: bash
     - name: Install OpenFOAM on Linux (with caching)
       if: steps.prep.outputs.apt-package && inputs.cache && !job.container
-      uses: eth-pkg/[email protected].5
+      uses: eth-pkg/[email protected].6
       with:
         packages: ${{ steps.prep.outputs.apt-package }}
     - name: Install OpenFOAM on Linux (without caching)