build(deps): bump the container-images group across 2 directories with 1 update

Bumps the container-images group with 1 update in the /packaging/docker/ubuntu-20.04 directory: buildkite/agent-base.
Bumps the container-images group with 1 update in the /packaging/docker/ubuntu-22.04 directory: buildkite/agent-base.


Updates `buildkite/agent-base` from `c3917ab` to `2476bcb`

Updates `buildkite/agent-base` from `0cb1d95` to `6b4726b`

---
updated-dependencies:
- dependency-name: buildkite/agent-base
  dependency-version: ubuntu-focal
  dependency-type: direct:production
  dependency-group: container-images
- dependency-name: buildkite/agent-base
  dependency-version: ubuntu-jammy
  dependency-type: direct:production
  dependency-group: container-images
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

packaging/docker/ubuntu-20.04/Dockerfile

@@ -1,6 +1,6 @@
 # syntax=docker/dockerfile:1.4
 
-FROM public.ecr.aws/buildkite/agent-base:ubuntu-focal@sha256:c3917ab9821967f2ba0434d4d430dbcdb0187e22ea7d1a28c08fac5cf021460b
+FROM public.ecr.aws/buildkite/agent-base:ubuntu-focal@sha256:2476bcb5ccf9d1f8ae6623170e51351d2b2de7634e52a2c7c12ac15c4317f927
 ARG TARGETOS
 ARG TARGETARCH
 

packaging/docker/ubuntu-22.04/Dockerfile

@@ -1,6 +1,6 @@
 # syntax=docker/dockerfile:1.4
 
-FROM public.ecr.aws/buildkite/agent-base:ubuntu-jammy@sha256:0cb1d95cf0d6707018018d66c06c26060f4d5c0d6ca71a445673a10f6649b86c
+FROM public.ecr.aws/buildkite/agent-base:ubuntu-jammy@sha256:6b4726b05b5576175cf5c9b0144d6d2353d12c74bc5ff579080bf28f6836fcc4
 ARG TARGETOS
 ARG TARGETARCH