ci(kitchen+travis): adjust matrix to add `opensuse-leap-15.2`

.travis.yml

     - env: INSTANCE=v3000-py3-centos-8-3000-3-py3
     # - env: INSTANCE=v3000-py3-centos-7-3000-3-py3
     - env: INSTANCE=v3000-py3-fedora-31-3000-3-py3
-    # - env: INSTANCE=v3000-py3-opensuse-leap-151-3000-3-py3
+    - env: INSTANCE=v3000-py3-opensuse-leap-152-3000-3-py3
     - env: INSTANCE=v3000-py3-amazonlinux-2-3000-3-py3
     - env: INSTANCE=v3000-py2-ubuntu-1804-3000-3-py2
     # - env: INSTANCE=v3000-py2-ubuntu-1604-3000-3-py2

kitchen.yml

   - name: fedora-31-3000-3-py3
     driver:
       image: netmanagers/salt-3000.3-py3:fedora-31
-  - name: opensuse-leap-151-3000-3-py3
+  - name: opensuse-leap-152-3000-3-py3
     driver:
-      image: netmanagers/salt-3000.3-py3:opensuse-leap-15.1
+      image: netmanagers/salt-3000.3-py3:opensuse-leap-15.2
       run_command: /usr/lib/systemd/systemd
-    # Workaround to avoid intermittent failures on `opensuse-leap-15.1`:
+    # Workaround to avoid intermittent failures on `opensuse-leap-15.2`:
     # => SCP did not finish successfully (255):  (Net::SCP::Error)
     transport:
       max_ssh_sessions: 1
       - centos-8-3000-3-py3
       - centos-7-3000-3-py3
       - fedora-31-3000-3-py3
-      - opensuse-leap-151-3000-3-py3
+      - opensuse-leap-152-3000-3-py3
       - amazonlinux-2-3000-3-py3
     provisioner:
       state_top: