Convert container to Bookworm + Python3.11

This matches what Zuul and Nodepool are doing. Getting off the older
images will alos allow OpenDev to stop building them. We update the
unittest job to python 3.11 in the process to better cover what people
will deploy.

Change-Id: Id631909640b015ffff9660f33a85c1b1bac375f8

.zuul.yaml

@@ -31,8 +31,8 @@
       - zuul-container-image
       - zuul-registry-container-image
       - nodepool-container-image
-      - python-builder-3.10-bullseye-container-image
-      - python-base-3.10-bullseye-container-image
+      - python-builder-3.11-bookworm-container-image
+      - python-base-3.11-bookworm-container-image
     provides:
       - zuul-operator-container-image
     vars: &image_vars
@@ -93,8 +93,8 @@
       - nodepool-container-image
     provides:
       - zuul-operator-container-image
-      - python-builder-3.10-bullseye-container-image
-      - python-base-3.10-bullseye-container-image
+      - python-builder-3.11-bookworm-container-image
+      - python-base-3.11-bookworm-container-image
     vars: *image_vars
 
 - job:

build/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:3.10-bullseye as builder
+FROM docker.io/opendevorg/python-builder:3.11-bookworm as builder
 
 COPY . /tmp/src
 RUN assemble
 
-FROM docker.io/opendevorg/python-base:3.10-bullseye
+FROM docker.io/opendevorg/python-base:3.11-bookworm
 
 COPY --from=builder /output/ /output
 RUN /output/install-from-bindep