cacheprovider: fix file-skipping feature for files in packages

`--lf` has a feature where if a certain `Module` (python file) does not
contain any failed tests, it is skipped entirely at the collector level
instead of being collected and each item skipped individually. When this
happens the collection summary looks like this:

    run-last-failure: rerun previous 1 failure (skipped 1 file)

However, this feature didn't work for `Module`s inside of `Package`s,
only for those directly beneath the `Session`.

Fix #11054.

Author: bluetech

changelog/11054.bugfix.rst

@@ -0,0 +1 @@
+Fixed ``--last-failed``'s "(skipped N files)" functionality for files inside of packages (directories with `__init__.py` files).

src/_pytest/cacheprovider.py

@@ -219,7 +219,7 @@ def __init__(self, lfplugin: "LFPlugin") -> None:
 
     @hookimpl(hookwrapper=True)
     def pytest_make_collect_report(self, collector: nodes.Collector):
-        if isinstance(collector, Session):
+        if isinstance(collector, (Session, Package)):
             out = yield
             res: CollectReport = out.get_result()
 

testing/test_cacheprovider.py

@@ -420,7 +420,13 @@ def test_fail(val):
         result = pytester.runpytest()
         result.stdout.fnmatch_lines(["*1 failed in*"])
 
-    def test_terminal_report_lastfailed(self, pytester: Pytester) -> None:
+    @pytest.mark.parametrize("parent", ("session", "package"))
+    def test_terminal_report_lastfailed(self, pytester: Pytester, parent: str) -> None:
+        if parent == "package":
+            pytester.makepyfile(
+                __init__="",
+            )
+
         test_a = pytester.makepyfile(
             test_a="""
             def test_a1(): pass