Set testenv explicitly

Signed-off-by: Christian König <ckoenig@posteo.de>

test/tox.centos_8.ini

@@ -1,8 +1,8 @@
 [tox]
 envlist = py3
 
-[testenv]
+[testenv:py3]
 allowlist_externals = docker
 deps = -rrequirements.txt
-commands = docker build -f _centos_8.Dockerfile -t pytest_pihole:test_container ../
-           pytest {posargs:-vv -n auto} ./test_any_automated_install.py ./test_any_utils.py ./test_centos_fedora_common_support.py ./test_centos_common_support.py
+commands =  docker build -f _centos_8.Dockerfile -t pytest_pihole:test_container ../
+            pytest {posargs:-vv -n auto} ./test_any_automated_install.py ./test_any_utils.py ./test_centos_fedora_common_support.py ./test_centos_common_support.py

test/tox.centos_9.ini

@@ -1,7 +1,7 @@
 [tox]
 envlist = py3
 
-[testenv]
+[testenv:py3]
 allowlist_externals = docker
 deps = -rrequirements.txt
 commands = docker build -f _centos_9.Dockerfile -t pytest_pihole:test_container ../

test/tox.debian_10.ini

@@ -1,7 +1,7 @@
 [tox]
 envlist = py3
 
-[testenv]
+[testenv:py3]
 allowlist_externals = docker
 deps = -rrequirements.txt
 commands = docker build -f _debian_10.Dockerfile -t pytest_pihole:test_container ../

test/tox.debian_11.ini

@@ -1,7 +1,7 @@
 [tox]
 envlist = py3
 
-[testenv]
+[testenv:py3]
 allowlist_externals = docker
 deps = -rrequirements.txt
 commands = docker build -f _debian_11.Dockerfile -t pytest_pihole:test_container ../

test/tox.fedora_35.ini

@@ -1,7 +1,7 @@
 [tox]
 envlist = py3
 
-[testenv]
+[testenv:py3]
 allowlist_externals = docker
 deps = -rrequirements.txt
 commands = docker build -f _fedora_35.Dockerfile -t pytest_pihole:test_container ../

test/tox.fedora_36.ini

@@ -1,7 +1,7 @@
 [tox]
 envlist = py3
 
-[testenv]
+[testenv:py3]
 allowlist_externals = docker
 deps = -rrequirements.txt
 commands = docker build -f _fedora_36.Dockerfile -t pytest_pihole:test_container ../

test/tox.ubuntu_20.ini

@@ -1,7 +1,7 @@
 [tox]
 envlist = py3
 
-[testenv]
+[testenv:py3]
 allowlist_externals = docker
 deps = -rrequirements.txt
 commands = docker build -f _ubuntu_20.Dockerfile -t pytest_pihole:test_container ../

test/tox.ubuntu_22.ini

@@ -1,7 +1,7 @@
 [tox]
 envlist = py3
 
-[testenv]
+[testenv:py3]
 allowlist_externals = docker
 deps = -rrequirements.txt
 commands = docker build -f _ubuntu_22.Dockerfile -t pytest_pihole:test_container ../