Add gherkin-official combinations to tox matrix

Author: youtux

tox.ini

@@ -1,7 +1,7 @@
 [tox]
 distshare = {homedir}/.tox/distshare
-envlist = py{3.9,3.10,3.11}-pytest{7.0,7.1,7.2,7.3,7.4,8.0,8.1,8.2,8.3,latest}-coverage
-          py{3.12,3.13}-pytest{7.3,7.4,8.0,8.1,8.2,8.3,latest}-coverage
+envlist = py{3.9,3.10,3.11}-pytest{7.0,7.1,7.2,7.3,7.4,8.0,8.1,8.2,8.3,latest}-gherkin_official{29,30,latest}-coverage
+          py{3.12,3.13}-pytest{7.3,7.4,8.0,8.1,8.2,8.3,latest}-gherkin_official{29,30,latest}-coverage
           py3.12-pytestlatest-xdist-coverage
           mypy
 
@@ -11,6 +11,10 @@ setenv =
     coverage: _PYTEST_CMD=coverage run -m pytest
     xdist: _PYTEST_MORE_ARGS=-n3 -rfsxX
 deps =
+    gherkin_officiallatest: gherkin-official
+    gherkin_official30: gherkin-official~=30.0.0
+    gherkin_official29: gherkin-official~=29.0.0
+
     pytestlatest: pytest
     pytest8.1: pytest~=8.1.0
     pytest8.0: pytest~=8.0.0