Build docs on 3.12

.github/workflows/ci.yml

@@ -120,7 +120,7 @@ jobs:
       - uses: actions/setup-python@v4
         with:
           # Keep in sync with tox/docs and .readthedocs.yaml.
-          python-version: "3.11"
+          python-version: "3.12"
           cache: pip
 
       - run: python -Im pip install tox

.readthedocs.yaml

@@ -5,7 +5,7 @@ build:
   os: ubuntu-22.04
   tools:
     # Keep version in sync with tox.ini/docs and ci.yml/docs.
-    python: "3.11"
+    python: "3.12"
 
 python:
   install:

docs/api.rst

@@ -442,10 +442,10 @@ All objects from ``attrs.validators`` are also available from ``attr.validators`
       ...     val = field(validator=attrs.validators.in_([1, 2, 3]))
       >>> C(State.ON, 1)
       C(state=<State.ON: 'on'>, val=1)
-      >>> C("on", 1)
+      >>> C("On", 1)
       Traceback (most recent call last):
          ...
-      ValueError: 'state' must be in <enum 'State'> (got 'on'), Attribute(name='state', default=NOTHING, validator=<in_ validator with options <enum 'State'>>, repr=True, eq=True, eq_key=None, order=True, order_key=None, hash=None, init=True, metadata=mappingproxy({}), type=None, converter=None, kw_only=False, inherited=False, on_setattr=None), <enum 'State'>, 'on')
+      ValueError: 'state' must be in <enum 'State'> (got 'On'), Attribute(name='state', default=NOTHING, validator=<in_ validator with options <enum 'State'>>, repr=True, eq=True, eq_key=None, order=True, order_key=None, hash=None, init=True, metadata=mappingproxy({}), type=None, converter=None, kw_only=False, inherited=False, on_setattr=None), <enum 'State'>, 'on')
       >>> C(State.ON, 4)
       Traceback (most recent call last):
       ...
@@ -536,7 +536,7 @@ All objects from ``attrs.validators`` are also available from ``attr.validators`
         >>> @define
         ... class User:
         ...     email = field(validator=attrs.validators.matches_re(
-        ...         "(^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$)"))
+        ...         r"(^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$)"))
         >>> User(email="user@example.com")
         User(email='user@example.com')
         >>> User(email="user@example.com@test.com")

tox.ini

@@ -54,7 +54,7 @@ commands =
 
 [testenv:docs]
 # Keep base_python in-sync with ci.yml/docs and .readthedocs.yaml.
-base_python = py311
+base_python = py312
 extras = docs
 commands =
     sphinx-build -n -T -W -b html -d {envtmpdir}/doctrees docs docs/_build/html