Update container version that includes cargo-audit 0.22

cargo-audit 0.22 is the first version that can parse cvss 4.0 scores
and avoid the following error in our pipelines:
  $ cargo audit -q --deny warnings
  error: error loading advisory database: parse error: TOML parse error at line 8, column 8
    |
  8 | cvss = "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N"
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  unsupported CVSS version: 4.0

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>

Author: stefano-garzarella

.buildkite/autogenerate_pipeline.py

@@ -60,7 +60,7 @@
 
 # This represents the version of the rust-vmm-container used
 # for running the tests.
-CONTAINER_VERSION = "gcb2ba77"
+CONTAINER_VERSION = "ga87ad68"
 # The suffix suggests that the dev image with `v{N}-riscv` tag is not to be
 # confused with real `riscv64` image (it's actually a `x86_64` image with
 # `qemu-system-riscv64` installed), since AWS yet has `riscv64` machines