[tests] Disable Python 3.6 CI tests

Bug: T347026
Change-Id: If17c04e554d1ece597042ad6de176ba3289b705e

tox.ini

@@ -5,8 +5,8 @@ skipsdist = True
 skip_missing_interpreters = True
 envlist =
     commit-message
-    flake8-{py36,py39}
-    hacking-{py36,py39}
+    flake8-py3{7,8,9}
+    hacking-py3{8,9}
 
 [params]
 # Note: tox 4 does not support multiple lines when doing parameters
@@ -16,7 +16,7 @@ generate_user_files = -W error::UserWarning -m pwb generate_user_files -family:w
 
 [testenv]
 basepython =
-    py36: python3.6
+    py36: python3.7
     py37: python3.7
     py38: python3.8
     py39: python3.9
@@ -28,15 +28,15 @@ usedevelop = True
 commands =
     python --version
     flake8: flake8 --version
-    flake8-py36: flake8 --color always --doctests {posargs} {[params]exclude}
+    flake8-py37: flake8 --color always --doctests {posargs} {[params]exclude}
     flake8-py38: flake8 --color always --doctests {posargs}
     flake8-py39: flake8 --color always --doctests {posargs}
 
     hacking: flake8 --version
     hacking: flake8 --format=default {posargs}
 
     deeptest: python {[params]generate_user_files}
-    deeptest-py36: python -m unittest discover -vv -p "*_tests.py"
+    deeptest-py37: python -m unittest discover -vv -p "*_tests.py"
     deeptest-py39: pytest
 
     fasttest: python {[params]generate_user_files}
@@ -52,8 +52,8 @@ deps =
     fasttest: mock
     fasttest: .[scripts]
 
-    fasttest-py36: .[html]
-    fasttest-py37: .[wikitextparser]
+    fasttest-py37: .[html]
+    fasttest-py38: .[wikitextparser]
 
     deeptest: .[html]
     deeptest: .[scripts]
@@ -62,7 +62,7 @@ deps =
     deeptest-py39: pytest-subtests >= 0.3.2
 
 [testenv:typing]
-basepython = python3.9
+basepython = python3.7
 deps = pytest-mypy
 commands =
     mypy --version
@@ -74,7 +74,7 @@ deps = commit-message-validator
 commands = commit-message-validator
 
 [testenv:doctest]
-basepython = python3
+basepython = python3.7
 commands =
     python {[params]generate_user_files}
     pytest --version