multilib-build.eclass: update to upstream

Remove EAPI check to be compatible with ChromeOS

BUG=b/425627696
TEST=presubmit
RELEASE_NOTE=None

cos-patch: security-high
Change-Id: I1b3e7324a894bffea86d0740321c7f1efd09ed06
Reviewed-on: https://cos-review.googlesource.com/c/third_party/overlays/eclass-overlay/+/107861
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: He Gao <hegao@google.com>