Update container images to python3.10

Do this so to take advantage of faster python3.10. This will also allow
us to drop 3.8 image builds making room for python 3.11.

Change-Id: I7f013a6616f98fe22420da68166eb15b6b7b7bdc

.zuul.yaml

@@ -19,6 +19,9 @@
     parent: opendev-build-docker-image
     description: Build OpenDev Docker images for statusbot
     provides: statusbot-container-image
+    requires:
+      - python-builder-3.10-bullseye-container-image
+      - python-base-3.10-bullseye-container-image
     vars: &statusbot_opendev_image_vars
       zuul_work_dir: src/opendev.org/opendev/statusbot
       docker_images:
@@ -31,6 +34,9 @@
     parent: opendev-upload-docker-image
     description: Build OpenDev statusbot Docker images and upload to Docker Hub.
     provides: statusbot-container-image
+    requires:
+      - python-builder-3.10-bullseye-container-image
+      - python-base-3.10-bullseye-container-image
     vars: *statusbot_opendev_image_vars
     secrets:
       - name: docker_credentials

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:3.10-bullseye as builder
 
 COPY . /tmp/src
 RUN assemble
 
-FROM opendevorg/python-base:3.8 as statusbot
+FROM opendevorg/python-base:3.10-bullseye as statusbot
 
 COPY --from=builder /output/ /output
 RUN /output/install-from-bindep

setup.cfg

@@ -17,6 +17,7 @@ classifier =
     Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7
     Programming Language :: Python :: 3.8
+    Programming Language :: Python :: 3.10
 
 [entry_points]
 console_scripts =