Update the registry docker image to bullseye

This updates the base image to bullseye. Buster has a shelf life now and
we should shift to bullseye.

Change-Id: Ia136695f00a9ba71fc8ffe984e9563e1061ff099

.zuul.yaml

@@ -22,6 +22,9 @@
     allowed-projects: zuul/zuul-registry
     run: playbooks/functional-test/run.yaml
     post-run: playbooks/functional-test/post.yaml
+    requires:
+      - python-builder-3.8-bullseye-container-image
+      - python-base-3.8-bullseye-container-image
     provides: zuul-registry-container-image
     nodeset: ubuntu-bionic
     vars: &image_vars
@@ -46,6 +49,9 @@
       name: docker_credentials
       secret: zuul-registry-dockerhub
       pass-to-parent: true
+    requires:
+      - python-builder-3.8-bullseye-container-image
+      - python-base-3.8-bullseye-container-image
     provides: zuul-registry-container-image
     vars: *image_vars
 

Dockerfile

@@ -13,12 +13,12 @@
 # You should have received a copy of the GNU General Public License
 # along with this software.  If not, see <http://www.gnu.org/licenses/>.
 
-FROM opendevorg/python-builder:3.8 as builder
+FROM opendevorg/python-builder:3.8-bullseye as builder
 
 COPY . /tmp/src
 RUN assemble
 
-FROM opendevorg/python-base:3.8 as zuul-registry
+FROM opendevorg/python-base:3.8-bullseye as zuul-registry
 
 COPY --from=builder /output/ /output
 RUN /output/install-from-bindep