Schedule deprecated legacy hook marks for removal in pytest 10

By the time pytest 10 is released, this will have been deprecated for
more than 5 years (0fdacb6), and the
alternative syntax available for over 10 years
(d2a5c7f), which seems like enough
time.

Removal will simplify PytestPluginManager and leave us with one way for
setting hookspec/hookimpl options (the plan after removal is to just
treat the old markers as normal markers, not hard-error on them).

Author: bluetech

doc/en/deprecations.rst

@@ -174,6 +174,8 @@ Python 3.3+ natively supports namespace packages without ``__init__.py``.
 Configuring hook specs/impls using markers
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
+.. deprecated:: 7.2
+
 Before pluggy, pytest's plugin library, was its own package and had a clear API,
 pytest just used ``pytest.mark`` to configure hooks.
 

src/_pytest/deprecated.py

@@ -39,7 +39,7 @@
 
 
 HOOK_LEGACY_MARKING = UnformattedWarning(
-    PytestDeprecationWarning,
+    PytestRemovedIn10Warning,
     "The hook{type} {fullname} uses old-style configuration options (marks or attributes).\n"
     "Please use the pytest.hook{type}({hook_opts}) decorator instead\n"
     " to configure the hooks.\n"