Remove restore-keys from GitHub actions cache

We do not require the restore keys for the cache so we can remove them
and default to the `key` itself.

Signed-off-by: Sascha Grunert <sgrunert@redhat.com>

.github/workflows/test.yml

@@ -79,7 +79,6 @@ jobs:
           path: |
             ~/.vagrant.d/boxes
           key: e2e-fedora-${{ hashFiles('hack/ci/Vagrantfile-fedora') }}
-          restore-keys: e2e-fedora-
       - uses: actions/download-artifact@fb598a63ae348fa914e94cd0ff38f362e927b741
         with:
           name: image
@@ -117,7 +116,6 @@ jobs:
           path: |
             ~/.vagrant.d/boxes
           key: e2e-ubuntu-${{ hashFiles('hack/ci/Vagrantfile-ubuntu') }}
-          restore-keys: e2e-ubuntu-
       - uses: actions/download-artifact@fb598a63ae348fa914e94cd0ff38f362e927b741
         with:
           name: image
@@ -158,7 +156,6 @@ jobs:
           path: |
             ~/.vagrant.d/boxes
           key: e2e-flatcar-${{ steps.vagrant-box.outputs.version }}-${{ hashFiles('hack/ci/Vagrantfile-flatcar') }}
-          restore-keys: e2e-flatcar-${{ steps.vagrant-box.outputs.version }}-
       - name: Upgrade vagrant box
         run: |
           ln -sf hack/ci/Vagrantfile-flatcar Vagrantfile