tests: check boostraplike setup

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

tox.ini

@@ -47,8 +47,21 @@ commands =
 description = verify build can run from source (bootstrap)
 setenv =
     PYTHONPATH = {toxinidir}/src
+skip_install = true
+deps =
+    toml; python_version<"3.11"
+    packaging
+    pep517
+    importlib-metadata; python_version<"3.8"
+    filelock
+    pytest
+    pytest-cov
+    pytest-mock
+    pytest-rerunfailures
+    pytest-xdist
+    wheel
+    setuptools
 commands =
-    python -E -m pip uninstall -y build
     pytest -ra {posargs:-n auto}
 
 [testenv:type]