Add PyPy3 test to tox

Signed-off-by: Arthit Suriyawongkul <arthit@gmail.com>

Author: bact

pyproject.toml

@@ -65,6 +65,15 @@ dependencies = ["tzdata; sys_platform == 'win32'"]
 
 [project.optional-dependencies]
 
+dev = [
+    "black>=25.11.0",
+    "bump-my-version>=1.2.6 ",
+    "coverage>=7.10.7",
+    "flake8>=7.3.0",
+    "ruff>=0.14.14",
+    "tox>=4.30.3",
+]
+
 abbreviation = ["khamyo>=0.2.0"]
 
 attacut = ["attacut>=1.0.6"]
@@ -320,7 +329,7 @@ select = [
 extend-ignore = ["E402", "E501", "E722", "S101", "S202", "S301", "S310"]
 
 [tool.tox]
-envlist = ["py39", "py310", "py311", "py312", "py313", "py3", "flake8"]
+envlist = ["py39", "py310", "py311", "py312", "py313", "py314", "py3", "pypy3", "flake8"]
 skip_missing_interpreters = true
 
 [tool.tox.testenv]
@@ -329,6 +338,13 @@ changedir = "tests"
 commands = ["discover"]
 deps = ["discover"]
 
+[tool.tox.envs.pypy3]
+basepython = "pypy3.10"
+setenv = { PYTHONPATH = "{toxinidir}:{toxinidir}/pythainlp" }
+changedir = "tests"
+commands = ["discover"]
+deps = ["discover"]
+
 [tool.tox.envs.flake8]
 basepython = "python"
 deps = ["flake8"]