Remove checked-in configuration

Both the bpf and bpf-next tree have suitable BPF selftest configurations
available for usage with the latest kernel now upstream. While we do
test on 4.9 and 5.5 kernels as well, there we just download prebuilt
binaries. The configuration we use for building selftests is always the
upstream one.
With this change we remove the checked-in configuration, as it is now no
longer needed.

Signed-off-by: Daniel Müller <deso@posteo.net>

.github/actions/vmtest/action.yml

@@ -41,12 +41,10 @@ runs:
     - name: Prepare to build BPF selftests
       shell: bash
       run: |
-        echo "::group::Prepare buidling selftest"
+        echo "::group::Prepare building selftest"
         cd .kernel
         cat tools/testing/selftests/bpf/config \
-            tools/testing/selftests/bpf/config.${{ inputs.arch }} \
-            ${{ github.workspace }}/travis-ci/vmtest/configs/config-latest \
-            ${{ github.workspace }}/travis-ci/vmtest/configs/config-latest.${{ inputs.arch }} 2> /dev/null > .config && :
+            tools/testing/selftests/bpf/config.${{ inputs.arch }} > .config
         make olddefconfig && make prepare
         cd -
         echo "::endgroup::"