Cleanup tox targets

Align tox targets with github workflows and fix targets
not associated with a specific python version to use
the python3 version installed on the host

.github/workflows/ci-units-types.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        python-version: ["3.8", "3.9", "3.10"]
+        python-version: ["3.9", "3.10", "3.11"]
 
     steps:
       - uses: actions/checkout@v3
@@ -26,4 +26,4 @@ jobs:
           python -m pip install tox
       - name: Run unit and type tests
         run: |
-          tox -e unit_py3_6,unit_py3_8,unit_py3_9,unit_py3_10
+          tox -e unit_py3_9,unit_py3_10,unit_py3_11

tox.ini

@@ -20,14 +20,12 @@ envlist =
     unit_py3_11,
     unit_py3_10,
     unit_py3_9,
-    unit_py3_8,
-    unit_py3_6,
     packagedoc
 
 
 [testenv]
 description =
-    {unit_py3_6,unit_py3_8,unit_py3_9,unit_py3_10,unit_py3_11}: Unit Test run with basepython set to {basepython}
+    {unit_py3_9,unit_py3_10,unit_py3_11}: Unit Test run with basepython set to {basepython}
     devel: Test KIWI
 allowlist_externals =
     bash
@@ -44,35 +42,17 @@ basepython =
     unit_py3_11: python3.11
     unit_py3_10: python3.10
     unit_py3_9: python3.9
-    unit_py3_8: python3.8
-    unit_py3_6: python3.6
     release: python3.10
+    check: python3
+    devel: python3
+    packagedoc: python3
 passenv =
     *
 usedevelop = True
 deps =
     -r.virtualenv.dev-requirements.txt
 
 
-# Unit Test run with basepython set to 3.6
-[testenv:unit_py3_6]
-setenv =
-    PYTHONPATH={toxinidir}/test
-deps = {[testenv:unit]deps}
-changedir=test/unit
-commands =
-    {[testenv:unit]commands}
-
-
-# Unit Test run with basepython set to 3.8
-[testenv:unit_py3_8]
-setenv =
-    PYTHONPATH={toxinidir}/test
-changedir=test/unit
-commands =
-    {[testenv:unit]commands}
-
-
 # Unit Test run with basepython set to 3.9
 [testenv:unit_py3_9]
 setenv =