libxml2: upgraded package to upstream

Upgraded dev-libs/libxml2 to version 2.9.10-r5 on amd64

BUG=b/181619636
TEST=presubmit
RELEASE_NOTE=Fixed CVE-2020-24977 in libxml2.

Change-Id: I8618562ec338d9e0f736aca5a23a9754b692373e
Reviewed-on: https://cos-review.googlesource.com/c/third_party/overlays/portage-stable/+/16090
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Anil Altinay <aaltinay@google.com>
12 files changed