fix(deps): update ghcr.io/containerbase/base docker tag to v13.21.0 (#906)

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

Author: renovate[bot]

Dockerfile

@@ -1,5 +1,5 @@
 # renovate: datasource=docker depName=ghcr.io/containerbase/base
-ARG CONTAINERBASE_VERSION=13.20.6
+ARG CONTAINERBASE_VERSION=13.21.0
 
 FROM ghcr.io/containerbase/base:${CONTAINERBASE_VERSION} as containerbase