chore(deps): update ubuntu:22.04 docker digest to 1aa979d (#363)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

discourse_rock/rockcraft.yaml

@@ -5,7 +5,7 @@ name: discourse
 summary: Discourse rock
 description: Discourse OCI image for the Discourse charm
 base: [email protected]
-# renovate: base: ubuntu:22.04@sha256:1ec65b2719518e27d4d25f104d93f9fac60dc437f81452302406825c46fcc9cb
+# renovate: base: ubuntu:22.04@sha256:1aa979d85661c488ce030ac292876cf6ed04535d3a237e49f61542d8e5de5ae0
 run-user: _daemon_  # UID/GID 584792
 license: Apache-2.0
 version: "1.0"