Fix python-augeas failure on Windows (v2) (#8951)

This PR is a new approach for fixing #8732 based on the discussions occurred in the first PR #8877.

This PR upgrades python-augeas to the latest version, and avoids tests failure of Windows because of this upgrade. To do so it leverages the [tox multi-platform feature](https://tox.readthedocs.io/en/latest/example/platform.html) and modifications to `tools/venv.py` in order to not install and not test `certbot-apache` on Windows.

* Unpin python-augeas and upgrade current pinnings

* Do not install certbot-apache in Windows dev environments

* Introduce tox specific win packages + remove certbot compatibility on windows

* Add libaugeas to sphinx build

* Redefine lint and mypy targets

* Keep the lint and mypy environments

.azure-pipelines/templates/jobs/standard-tests-jobs.yml

@@ -15,11 +15,11 @@ jobs:
         windows-py36:
           IMAGE_NAME: vs2017-win2016
           PYTHON_VERSION: 3.6
-          TOXENV: py36
+          TOXENV: py36-win
         windows-py38-cover:
           IMAGE_NAME: vs2017-win2016
           PYTHON_VERSION: 3.8
-          TOXENV: py38-cover
+          TOXENV: py38-cover-win
         windows-integration-certbot:
           IMAGE_NAME: vs2017-win2016
           PYTHON_VERSION: 3.8
@@ -43,11 +43,11 @@ jobs:
         linux-py39-lint:
           IMAGE_NAME: ubuntu-18.04
           PYTHON_VERSION: 3.9
-          TOXENV: lint
+          TOXENV: lint-posix
         linux-py39-mypy:
           IMAGE_NAME: ubuntu-18.04
           PYTHON_VERSION: 3.9
-          TOXENV: mypy
+          TOXENV: mypy-posix
         linux-integration:
           IMAGE_NAME: ubuntu-18.04
           PYTHON_VERSION: 3.8

.azure-pipelines/templates/steps/sphinx-steps.yml

@@ -1,5 +1,8 @@
 steps:
   - bash: |
+      set -e
+      sudo apt-get update
+      sudo apt-get install -y --no-install-recommends libaugeas0
       FINAL_STATUS=0
       declare -a FAILED_BUILDS
       tools/venv.py