remove .markers attribute which was added in development and after 2.2.4

so never released.  Rather extend keywords to also exist on nodes. Assigning
to node.keywords will make the value appear on all subchildren's
keywords.

_pytest/python.py

@@ -883,10 +883,10 @@ class Function(FunctionMixin, pytest.Item, FuncargnamesCompatAttr):
             self.obj = callobj
 
         for name, val in (py.builtin._getfuncdict(self.obj) or {}).items():
-            setattr(self.markers, name, val)
+            self.keywords[name] = val
         if keywords:
             for name, val in keywords.items():
-                setattr(self.markers, name, val)
+                self.keywords[name] = val
 
         fm = self.session._fixturemanager
         self._fixtureinfo = fi = fm.getfixtureinfo(self.parent,
@@ -1066,7 +1066,7 @@ class FixtureRequest(FuncargnamesCompatAttr):
 
     @property
     def keywords(self):
-        """ (deprecated, use node.markers class) dictionary of markers. """
+        """ keywords/markers dictionary for the underlying node. """
         return self._pyfuncitem.keywords
 
     @property
@@ -1099,7 +1099,10 @@ class FixtureRequest(FuncargnamesCompatAttr):
         :arg marker: a :py:class:`_pytest.mark.MarkDecorator` object
             created by a call to ``py.test.mark.NAME(...)``.
         """
-        self.node.applymarker(marker)
+        try:
+            self.node.keywords[marker.markname] = marker
+        except AttributeError:
+            raise ValueError(marker)
 
     def raiseerror(self, msg):
         """ raise a FixtureLookupError with the given message. """