Simplify tox.ini file

and split it into sections for easier reading

tox.ini

@@ -8,25 +8,14 @@ envlist =
     migrations
 # Use the Tox at least 4.16. If not available it will be auto-provisioned.
 minversion = 4.16
-
-# Configure special Tox environment used for isolated building of the source
-# package.
-[testenv:.package]
-# Use the default Python 3 version available on the system.
-# NOTE: This makes it portable to CI systems where only one particular Python 3
-# version is installed.
-basepython = python3
-
-# Use setuptools suitable for google storage connectors.
-
+# Make it possible to override the base python with the environment name.
+ignore_base_python_conflict = true
 
 [testenv]
-allowlist_externals = 
-    bash
-basepython =
-    py311{,-storage-credentials}: python3.11
-    py312{,-storage-credentials}: python3.12
-    docs,linters,packaging,migrations: python3.12
+# Use python 3.12 if it cannot be infered from the environment.
+# See https://tox.wiki/en/latest/user_guide.html#test-environments for rules
+# how basepython is selected from the environment name.
+basepython = python3.12
 extras =
     # Always include storage extras or connectors related tests will fail.
     py3{11,12}{,-storage-credentials}:
@@ -56,37 +45,46 @@ ignore_errors =
     # Run all linters to see their output even if one of them fails.
     linters: true
 
+[testenv:py3{11,12}{,-storage-credentials}]
 commands =
     # General tests commands:
     # Print the environment and run tests.
-    py3{11,12}{,-storage-credentials}: coverage run tests/manage.py test {env:TEST_SUITE:resolwe} \
-    py3{11,12}-storage-credentials:     --pattern storage_credentials_test_*.py \
-    py3{11,12}{,-storage-credentials}:     --noinput --verbosity=2 --parallel
-    py3{11,12}{,-storage-credentials}: coverage combine
+    coverage run tests/manage.py test {env:TEST_SUITE:resolwe} \
+        storage-credentials:  --pattern storage_credentials_test_*.py \
+    --noinput --verbosity=2 --parallel
+    coverage combine
 
-    # Docs commands:
-    # Build documentation.
-    docs: sphinx-build ./docs/ build/sphinx/html --fail-on-warning --fresh-env
+[testenv:migrations]
+allowlist_externals =
+    bash
+    psql
+commands = 
+    python tests/manage.py migrate
+    bash -c '[[ $(./tests/manage.py makemigrations --dry-run) = '\
+            '"No changes detected" ]] || exit 1'
+
+[testenv:packaging]
+commands =
+    # Confirm that items checked into git are in sdist.
+    check-manifest
+    # Verify package metadata and confirm the long_description will render
+    # correctly on PyPI.
+    python -m build
+    python -m twine check --strict dist/*
 
+[testenv:linters]
+commands =
     # Linter commands:
     # Check code formating with black.
-    linters: black --check resolwe
+    black --check resolwe
     # Check order of imports.
-    linters: isort --check-only --diff resolwe
+    isort --check-only --diff resolwe
     # Run PyFlakes and Ned Batchelder's McCabe script.
-    linters: flake8 resolwe
+    flake8 resolwe
     # Check documentation formatting (PEP 257).
-    linters: pydocstyle resolwe --match='(?!test[_s]).*\.py'
+    pydocstyle resolwe --match='(?!test[_s]).*\.py'
 
-    # Packaging commands:
-    # Confirm that items checked into git are in sdist.
-    packaging: check-manifest
-    # Verify package metadata and confirm the long_description will render
-    # correctly on PyPI.
-    packaging: python -m build
-    packaging: python -m twine check --strict dist/*
-
-    # Migrations commands:
-    migrations: python tests/manage.py migrate
-    migrations: bash -c '[[ $(./tests/manage.py makemigrations --dry-run) = '\
-    migrations:     '"No changes detected" ]] || exit 1'
+[testenv:docs]
+commands =
+    # Build documentation.
+    sphinx-build ./docs/ build/sphinx/html --fail-on-warning --fresh-env