add Ubuntu 22.04 unit test job to CircleCI

.circleci/config.yml

@@ -39,6 +39,8 @@ dockerhub-auth-template: &DOCKERHUB_AUTH
         <<: *DOCKERHUB_CONTEXT
     - "build-image-ubuntu-20-04":
         <<: *DOCKERHUB_CONTEXT
+    - "build-image-ubuntu-22-04":
+        <<: *DOCKERHUB_CONTEXT
     - "build-image-fedora-35":
         <<: *DOCKERHUB_CONTEXT
     - "build-image-oraclelinux-8":
@@ -78,6 +80,9 @@ workflows:
       - "ubuntu-20-04":
           {}
 
+      - "ubuntu-22-04":
+          {}
+
       # Equivalent to RHEL 8; CentOS 8 is dead.
       - "oraclelinux-8":
           {}
@@ -333,6 +338,16 @@ jobs:
       <<: *UTF_8_ENVIRONMENT
       TAHOE_LAFS_TOX_ENVIRONMENT: "py39"
 
+  ubuntu-22-04:
+    <<: *DEBIAN
+    docker:
+      - <<: *DOCKERHUB_AUTH
+        image: "tahoelafsci/ubuntu:22.04-py3.10"
+        user: "nobody"
+    environment:
+      <<: *UTF_8_ENVIRONMENT
+      TAHOE_LAFS_TOX_ENVIRONMENT: "py310"
+
   oraclelinux-8: &RHEL_DERIV
     docker:
       - <<: *DOCKERHUB_AUTH
@@ -479,6 +494,15 @@ jobs:
       PYTHON_VERSION: "3.9"
 
 
+  build-image-ubuntu-22-04:
+    <<: *BUILD_IMAGE
+
+    environment:
+      DISTRO: "ubuntu"
+      TAG: "22.04"
+      PYTHON_VERSION: "3.10"
+
+
   build-image-oraclelinux-8:
     <<: *BUILD_IMAGE