pylint: Skip unspecified-encoding

Pylint 2.10 introduced new checker:
> It is better to specify an encoding when opening documents. Using the
  system default implicitly can create problems on other operating
  systems. See https://www.python.org/dev/peps/pep-0597/

According to that PEP:
> open(filename) isn't explicit about which encoding is expected:
  - If ASCII is assumed, this isn't a bug, but may result in decreased
    performance on Windows, particularly with non-Latin-1 locale
    encodings
  - If UTF-8 is assumed, this may be a bug or a platform-specific script
  - If the locale encoding is assumed, the behavior is as expected (but
    could change if future versions of Python modify the default)

IPA requires UTF-8 environments.

Fixes: https://pagure.io/freeipa/issue/9117
Signed-off-by: Stanislav Levin <slev@altlinux.org>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>

pylintrc

@@ -112,6 +112,7 @@ disable=
     consider-using-f-string,  # pylint 2.11.0, format can be more readable
     use-dict-literal,  # pylint 2.10.0 dict vs {}
     use-list-literal,  # pylint 2.10.0 list() vs []
+    unspecified-encoding,  # pylint 2.10.0, ASCII or UTF8 and platform-specific
 
 [REPORTS]