Update the underlying python containers to "3.10-bookworm"

The existing 3.9 is based on debian buster and isn't getting security
updates ... or any updates really.  This change updates to a base
container that will get updates for a while.

I picked 3.10 rather than 3.11 as 3.10 is part of the bobcat[1]

[1] https://governance.openstack.org/tc/reference/runtimes/2023.2.html

Change-Id: I606389a81ab189b1abf2c700acf5c5543a09165a

.zuul.yaml

@@ -161,8 +161,8 @@
     description: Build Docker images.
     allowed-projects: openstack/python-openstackclient
     requires:
-      - python-builder-3.9-container-image
-      - python-base-3.9-container-image
+      - python-builder-3.10-bookworm-container-image
+      - python-base-3.10-bookworm-container-image
     provides: osc-container-image
     vars: &osc_image_vars
       docker_images:
@@ -175,8 +175,8 @@
     description: Build Docker images and upload to Docker Hub.
     allowed-projects: openstack/python-openstackclient
     requires:
-      - python-builder-3.9-container-image
-      - python-base-3.9-container-image
+      - python-builder-3.10-bookworm-container-image
+      - python-base-3.10-bookworm-container-image
     provides: osc-container-image
     secrets:
       - name: docker_credentials

Dockerfile

@@ -13,12 +13,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-FROM docker.io/opendevorg/python-builder:3.9 as builder
+FROM docker.io/opendevorg/python-builder:3.10-bookworm as builder
 
 COPY . /tmp/src
 RUN assemble
 
-FROM docker.io/opendevorg/python-base:3.9
+FROM docker.io/opendevorg/python-base:3.10-bookworm
 
 COPY --from=builder /output/ /output
 RUN /output/install-from-bindep