build: 添加Python3.13支持并更新 tox 配置

1. 新增Python3.13版本的分类支持
2. 启用isolated_build模式，切换依赖安装为.[dev]
3. 简化pytest执行参数，新增传递更多环境变量

tox.ini

@@ -1,4 +1,5 @@
 [tox]
+isolated_build = true
 envlist = py38, py39, py310, py311, py312, py313
 min_version = 4.0
 requires = tox-uv
@@ -7,12 +8,14 @@ skipsdist = true
 [testenv]
 uv_sync = true
 deps =
-    .
-    .[tox]
+    .[dev]
 commands =
-    pytest -m "not slow" -n 2 --dist=loadfile {posargs}
-passenv = *
+    pytest -m "not slow" {posargs}
+passenv =
+    CI
+    GITHUB_*
+    UV_*
+    PYTHON*
 setenv =
     PYTHONPATH = {toxinidir}/src
     PYTHONDONTWRITEBYTECODE = 1
-    QT_QPA_PLATFORM = offscreen