Fix failing CI jobs (pypa#4078)

docs/conf.py

@@ -200,7 +200,12 @@
 
 # Allow linking objects on other Sphinx sites seamlessly:
 intersphinx_mapping.update(
-    python=('https://docs.python.org/3', None),
+    # python=('https://docs.python.org/3', None),
+    python=('https://docs.python.org/3.11/', None),
+    # ^-- Python 3.11 is required because it still contains `distutils`.
+    #     Just leaving it as `3` would imply 3.12+, but that causes an
+    #     error with the cross references to disutils functions.
+    #     Inventory cache may cause errors, deleting it solves the problem.
 )
 
 # Add support for the unreleased "next-version" change notes

tox.ini

@@ -13,7 +13,7 @@ commands =
 usedevelop = True
 extras =
 	testing
-passenv =
+pass_env =
 	SETUPTOOLS_USE_DISTUTILS
 	PRE_BUILT_SETUPTOOLS_WHEEL
 	PRE_BUILT_SETUPTOOLS_SDIST
@@ -25,8 +25,8 @@ passenv =
 [testenv:integration]
 deps = {[testenv]deps}
 extras = testing-integration
-passenv =
-	{[testenv]passenv}
+pass_env =
+	{[testenv]pass_env}
 	DOWNLOAD_PATH
 setenv =
     PROJECT_ROOT = {toxinidir}