fix(btf): skip CONFIG_DEBUG_INFO_BTF on 5.10 kernels

5.10 kernel toolchain lacks libelf support for BTF
generation. Only enable BTF on 5.15+ kernels.

.github/workflows/build.yml

@@ -202,6 +202,7 @@ jobs:
       uses: ./.github/actions/misc
 
     - name: Enable BTF
+      if: ${{ inputs.kernel_version != '5.10' }}
       uses: ./.github/actions/set-kernel-config
       with:
         config_list: |