tests/test_general.py: test_4746(): fix call to archive.add().

Previously it only worked if a file `foo` existed in current directory.

Author: julian-smith-artifex-com

tests/test_general.py

@@ -2184,4 +2184,4 @@ def process_document(document):
 
 def test_4746():
     archive = pymupdf.Archive('.')
-    archive.add('foo', __file__)
+    archive.add(__file__, 'foo')