diff --git a/MANIFEST.in b/MANIFEST.in
deleted file mode 100644
index c0928d55..00000000
--- a/MANIFEST.in
+++ /dev/null
@@ -1,5 +0,0 @@
-exclude .appveyor.yml
-exclude .gitignore
-exclude .pre-commit-config.yaml
-exclude .travis.yml
-prune .github
diff --git a/pyproject.toml b/pyproject.toml
index d65a24dc..8e5e817e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -54,18 +54,15 @@ testing = ["filelock"]
 psutil = ["psutil>=3.0"]
 setproctitle = ["setproctitle"]
 
-[tool.setuptools]
-zip-safe = false
-platforms = [
-    "linux",
-    "osx",
-    "win32",
-]
-include-package-data = false
-
 [tool.setuptools_scm]
 write_to = "src/xdist/_version.py"
 
+[tool.pytest.ini_options]
+# pytest-services also defines a worker_id fixture, disable
+# it so they don't conflict with each other (#611).
+addopts = "-ra -p no:pytest-services"
+testpaths = ["testing"]
+
 [tool.ruff]
 src = ["src"]
 
diff --git a/tox.ini b/tox.ini
index 6a3e9db2..f5831737 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,34 +1,26 @@
 [tox]
-envlist=
+envlist =
   linting
   py{38,39,310,311,312}-pytestlatest
   py310-pytestmain
   py310-psutil
   py310-setproctitle
 isolated_build = true
+
 [testenv]
-extras = testing
+extras =
+  testing
+  psutil: psutil
+  setproctitle: setproctitle
 deps =
   pytestmin: pytest==7.0.0
   pytestlatest: pytest
   pytestmain: git+https://github.com/pytest-dev/pytest.git
-commands=
-  pytest {posargs}
-
-[testenv:py310-psutil]
-extras =
-  testing
-  psutil
 commands =
-  pytest {posargs:-k psutil}
-
-[testenv:py310-setproctitle]
-extras =
-  testing
-  setproctitle
-deps = pytest
-commands =
-  pytest {posargs}
+  pytest {posargs:{env:_XDIST_TOX_DEFAULT_POSARGS:}}
+setenv =
+  _XDIST_TOX_DEFAULT_POSARGS={env:_XDIST_TOX_POSARGS_PSUTIL:}
+  psutil: _XDIST_TOX_POSARGS_PSUTIL=-k psutil
 
 [testenv:linting]
 skip_install = True
@@ -39,9 +31,8 @@ deps =
 commands = pre-commit run --all-files --show-diff-on-failure
 
 [testenv:release]
-changedir=
+changedir =
 description = do a release, required posarg of the version number
-basepython = python3.10
 skipsdist = True
 usedevelop = True
 passenv = *
@@ -51,16 +42,9 @@ commands =
   towncrier build --version {posargs} --yes
 
 [testenv:docs]
-basepython = python3.10
 usedevelop = True
 deps =
     sphinx
     sphinx_rtd_theme
 commands =
     sphinx-build -W --keep-going -b html docs docs/_build/html {posargs:}
-
-[pytest]
-# pytest-services also defines a worker_id fixture, disable
-# it so they don't conflict with each other (#611).
-addopts = -ra -p no:pytest-services
-testpaths = testing