tests: adjust mime type expectations for .rtf (#22)

The test checks the mime type of .rtf filename. The check is based
on stdlib's `mimetypes.guess_type(name, strict=False)` which in
turn depends on provider of mime types mapping.
CPython's default mapping for rtf:
https://github.com/python/cpython/blob/3.14/Lib/mimetypes.py#L650
https://github.com/python/cpython/blob/3.14/Lib/mimetypes.py#L678-L683

$ python3 -c 'import mimetypes; mimetypes.knownfiles=[]; mimetypes.init(); print(mimetypes.types_map[".rtf"])'
text/rtf

`mimetypes` tries next providers of mime data by default:
$ python3 -c 'import mimetypes; print(mimetypes.knownfiles)'
['/etc/mime.types', '/etc/httpd/mime.types', '/etc/httpd/conf/mime.types', '/etc/apache/mime.types', '/etc/apache2/mime.types', '/usr/local/etc/httpd/conf/mime.types', '/usr/local/lib/netscape/mime.types', '/usr/local/etc/httpd/conf/mime.types', '/usr/local/etc/mime.types']

With installed /etc/mime.types (mailcap):
$ python3 -c 'import mimetypes; mimetypes.init(); print(mimetypes.types_map[".rtf"])'
application/rtf

According to https://www.iana.org/assignments/media-types/media-types.xhtml
both are possible.

Fixes: #21

Signed-off-by: Stanislav Levin <[email protected]>
Co-authored-by: Michael Howitz <[email protected]>

Author: stanislavlevin

src/zope/contenttype/tests/testContentTypes.py

@@ -60,7 +60,8 @@ def test_guess_content_type(self):
         ctype, _encoding = guess_content_type()
         self.assertEqual(ctype, "text/x-unknown-content-type")
         ctype, _encoding = guess_content_type("abc.rtf")
-        self.assertEqual(ctype, "application/rtf")
+        # both are possible
+        self.assertIn(ctype, ("application/rtf", "text/rtf"))
 
     def test_add_one_file(self):
         from zope.contenttype import add_files