Apply suggestions from code review

Co-authored-by: Zac Hatfield-Dodds <zac.hatfield.dodds@gmail.com>

doc/en/how-to/fixtures.rst

@@ -1752,7 +1752,7 @@ into an ini-file:
         def my_fixture_that_sadly_wont_use_my_other_fixture():
             ...
 
-    Currently this will generate a deprecation warning.
+    This generates a deprecation warning, and will become an error in Pytest 8.
 
 .. _`override fixtures`:
 

src/_pytest/deprecated.py

@@ -122,7 +122,7 @@ HOOK_LEGACY_MARKING = UnformattedWarning(
     "#configuring-hook-specs-impls-using-markers",
 )
 
-MARKED_FIXTURE = PytestDeprecationWarning(
+MARKED_FIXTURE = PytestRemovedIn8Warning(
     "Marks applied to fixtures have no effect\n"
     "See docs: https://docs.pytest.org/en/stable/deprecations.html#applying-a-mark-to-a-fixture-function"
 )

testing/deprecated_test.py

@@ -284,7 +284,7 @@ def test_importing_instance_is_deprecated(pytester: Pytester) -> None:
 def test_fixture_disallow_on_marked_functions():
     """Test that applying @pytest.fixture to a marked function warns (#3364)."""
     with pytest.warns(
-        pytest.PytestDeprecationWarning,
+        pytest.PytestRemovedIn8Warning,
         match=r"Marks applied to fixtures have no effect",
     ) as record:
 
@@ -303,7 +303,7 @@ def test_fixture_disallow_on_marked_functions():
 def test_fixture_disallow_marks_on_fixtures():
     """Test that applying a mark to a fixture warns (#3364)."""
     with pytest.warns(
-        pytest.PytestDeprecationWarning,
+        pytest.PytestRemovedIn8Warning,
         match=r"Marks applied to fixtures have no effect",
     ) as record:
 
@@ -319,7 +319,7 @@ def test_fixture_disallow_marks_on_fixtures():
 def test_fixture_disallowed_between_marks():
     """Test that applying a mark to a fixture warns (#3364)."""
     with pytest.warns(
-        pytest.PytestDeprecationWarning,
+        pytest.PytestRemovedIn8Warning,
         match=r"Marks applied to fixtures have no effect",
     ) as record: