Different tox.

templates/tox.ini.j2

@@ -1,5 +1,5 @@
 [tox]
-envlist = ansible-2.{12,13,14,15,16,17}
+envlist = ansible-2.{15,16,17}
 skipsdist = true
 
 [testenv]
@@ -13,26 +13,8 @@ setenv =
 
 passenv = namespace, image, tag, DOCKER_HOST
 
-[testenv:ansible-2.12]
-basepython = python3.8
-deps =
-    -rrequirements.txt
-    ansible-core==2.12.*
-    ansible-lint==5.*
-
-[testenv:ansible-2.13]
-basepython = python3.8
-deps =
-    -rrequirements.txt
-    ansible-core==2.13.*
-    ansible-lint==5.*
-
-[testenv:ansible-2.14]
-basepython = python3.9
-deps =
-    -rrequirements.txt
-    ansible-core==2.14.*
-    ansible-lint==6.*
+# Test supported releases of ansible-core. See:
+# https://docs.ansible.com/ansible/latest/reference_appendices/release_and_maintenance.html#ansible-core-support-matrix
 
 [testenv:ansible-2.15]
 basepython = python3.9
@@ -54,3 +36,13 @@ deps =
     -rrequirements.txt
     ansible-core==2.17.*
     ansible-lint==24.*
+
+# Future work, not releases, just prepared. See:
+# https://docs.ansible.com/ansible/devel//roadmap/ROADMAP_2_18.html
+# Note: enable python3.13 in `vars/main.yml` as well.
+# [testenv:ansible-2.18]
+# basepython = python3.13
+# deps =
+#     -rrequirements.txt
+#     ansible-core==2.18.*
+#     ansible-lint==24.*