migrate to psyplot-plugin-template

this MR migrates everything to the psyplot-plugin-template and implements compatibility fixes with the latest libraries

.circleci/config.yml

-version: 2.1
-
-orbs:
-  psyplot: psyplot/psyplot-ci-orb@1.5.25
-  mattermost-plugin-notify: nathanaelhoun/mattermost-plugin-notify@1.2.0
-
-executors:
-  default: psyplot/default
-  macos: psyplot/macos
-
-parameters:
-  unit-test-executor:
-    description: Executor for the unit tests. Can be default or macos
-    type: string
-    default: default
-  deploy-release:
-    description: Deploy the comment as a new release to github and pypi
-    type: boolean
-    default: false
-  run-tests:
-    description: Run the test suite
-    type: boolean
-    default: true
-  build_docs:
-    description: Build the documentation
-    type: boolean
-    default: true
-
-workflows:
-  build-and-test:
-    unless: << pipeline.parameters.deploy-release >>
-    jobs:
-      - psyplot/install-and-build:
-          name: install
-          exec_environment: << pipeline.parameters.unit-test-executor >>
-          setup_env: true
-          build_args: "--no-test"
-          build_docs: << pipeline.parameters.build_docs >>
-      - psyplot/test-parallel:
-          name: run-tests
-          parallelism: 1
-          pytest_args: --cov=psyplot_gui
-          run-job: << pipeline.parameters.run-tests >>
-          requires:
-            - install
-      - psyplot/build-docs:
-          name: test-docs
-          run-job: << pipeline.parameters.build_docs >>
-          builders: linkcheck
-          requires:
-            - install
-      - mattermost-plugin-notify/approval-notification:
-          name: notify-deploy
-          context: mattermost
-          message: >-
-            Hello @all! A workflow on https://app.circleci.com/pipelines/github/psyplot/psyplot-gui is awaiting your approval.
-            Please check the uploaded docs and builds prior to approval.
-          requires:
-            - run-tests
-            - test-docs
-      - hold-for-deploy:
-          type: approval
-          requires:
-            - notify-deploy
-      - psyplot/deploy-pkg:
-          exec_environment: << pipeline.parameters.unit-test-executor >>
-          context: anaconda
-          requires:
-            - hold-for-deploy
-      - psyplot/deploy-docs:
-          fingerprint: "19:54:3e:9e:7b:73:1c:45:ee:4c:7b:73:8a:46:96:3a"
-          run-job: << pipeline.parameters.build_docs >>
-          requires:
-            - hold-for-deploy
-          filters:
-            branches:
-              only: master
-      - psyplot/trigger-release-workflow:
-          context: trigger-release
-          filters:
-            branches:
-              only: master
-          requires:
-            - psyplot/deploy-pkg
-            - psyplot/deploy-docs
-  publish-release:
-    when: << pipeline.parameters.deploy-release >>
-    jobs:
-      - psyplot/create-tag:
-          ssh-fingerprints: "19:54:3e:9e:7b:73:1c:45:ee:4c:7b:73:8a:46:96:3a"
-          context: psyplot-admin
-          user-name: psyplot-admin
-          publish-release: true
-          publish-version-tag: true
-      - mattermost-plugin-notify/approval-notification:
-          name: notify-release
-          context: mattermost
-          message: >-
-            Hello @all! A new release has been created at https://github.com/psyplot/psyplot-gui/releases.
-            Please review it carefully, publish it and approve the upload to pypi.
-          requires:
-            - psyplot/create-tag
-      - hold-for-pypi:
-          type: approval
-          requires:
-            - notify-release
-      - psyplot/deploy-pypi:
-          context: pypi
-          requires:
-            - hold-for-pypi
-          filters:
-            branches:
-              only: master