Update salt_factories_default_root_dir GH runners

Updates salt_factories_default_root_dir to use $RUNNER_TEMP if running
in CI and using Windows. This is setup by the Github Runner and
should be on the same disk as the checked out repo.

Without doing that, the salt_factories_default_root_dir will be in the
user's temp dir which is on a different disk. This causes the fileserver
to throw an error as it tries to combine file_roots from the repo and
pytest-salt-factories.

tests/conftest.py

@@ -16,6 +16,7 @@ import _pytest.logging
 import _pytest.skipping
 import more_itertools
 import pytest
+import pytestskipmarkers
 
 import salt
 import salt._logging
@@ -426,7 +427,8 @@ def pytest_itemcollected(item):
             pytest.fail(
                 "The test {!r} appears to be written for pytest but it's not under"
                 " {!r}. Please move it there.".format(
-                    item.nodeid, str(PYTESTS_DIR.relative_to(CODE_DIR)), pytrace=False
+                    item.nodeid,
+                    str(PYTESTS_DIR.relative_to(CODE_DIR)),
                 )
             )
 
@@ -801,6 +803,12 @@ def salt_factories_default_root_dir(salt_factories_default_root_dir):
         dictionary, then that's the value used, and not the one returned by
         this fixture.
     """
+    if os.environ.get("CI") and pytestskipmarkers.utils.platform.is_windows():
+        tempdir = pathlib.Path(
+            os.environ.get("RUNNER_TEMP", r"C:\Windows\Temp")
+        ).resolve()
+        return tempdir / "stsuite"
+
     return salt_factories_default_root_dir / "stsuite"