move test for pickling

Moved "test_issue_1231_pickling.py" to "integration_tests",
because of the long runtime (for a unit test).

Author: mozman

…st_10_issues/test_issue_1231_pickling.py …ration_tests/test_issue_1231_pickling.pytests/test_10_issues/test_issue_1231_pickling.py renamed to integration_tests/test_issue_1231_pickling.py tests/test_10_issues/test_issue_1231_pickling.py renamed to integration_tests/test_issue_1231_pickling.py

@@ -11,7 +11,7 @@
 import ezdxf
 from ezdxf.document import Drawing
 
-EXAMPLES = Path(__file__).parent.parent.parent / "examples_dxf"
+EXAMPLES = Path(__file__).parent.parent / "examples_dxf"
 
 
 def example_dxfs() -> Iterator[Path]: