Inconsistent type narrowing for attribute accesses involving asymmetric descriptors

See https://github.com/microsoft/pyright/issues/11233 for additional context.

Example of incorrect behavior: [Playground](https://pyright-play.net/?strict=true&code=GYJw9gtgBALgngBwJYDsDmUkQWEMoCCKcANFAOICmKlISAxmQCqKUBqAhiAFDdNQBeKCwTsuACigAiJlKgBKbgFVBw1pxCSpSuYu70ANhwDOxqAEkUxmBxQwkHe%2BgIwYmitVoMA2sLIqAXQUALm4ocIATSmAoAH1Y40oYeMlEg2AyVGtbekpgwmIyADcOAwBXPKgVAB8oADkwGgUoAFoAPnrGvLDw3oA6Ad5eqJj4tCSUqDSMzCsbFFz8olIoMAB3GhAl4lUGpvlWjv5ave7e-sH9I1MoAAUkazADUPCAIy4QSgMAGWo0GAAFvlUDAeiM4rFUEhkrFUl8Zu8QJ8fn9AcC7GQAPTNdqdGgvC59XiGExmADC61eYDgBKgAKe1lo%2BUs2TsDicaBcbl890eBjIMDKCAMlF8IKgQQCvH0qgpaypcHEinofXpBkZIFUkgAbGRFKTaPgVWqNZgzCgwPhTtwEHQ7JJjQyYLQ%2Bojkb90ICFEA)

Assignment in a different scope fixes the issue: [Playground](https://pyright-play.net/?strict=true&code=GYJw9gtgBALgngBwJYDsDmUkQWEMoCCKcANFAOICmKlISAxmQCqKUBqAhiAFDdNQBeKCwTsuACigAiJlKgBKbgFVBw1pxCSpSuYu70ANhwDOxqAEkUxmBxQwkHe%2BgIwYmitVoMA2sLIqAXQUALm4ocIATSmAoAH1Y40oYeMlEg2AyVGtbekpgwmIyADcOAwBXPKgVAB8oADkwGgUoAFoAPnrGvLDw3oA6Ad5eqJj4tCSUqDSMzCsbFFz8olIoMAB3GhAl4lUGpvlWjv5ave7e-sH9I1MoAAUkazADUPCAIy4QSgMAGWo0GAAFvlUDAeiM4rFUEhkrFUl8Zu8QJ8fn9AcC7GQAPTNdqdGgvC59XiGExmADC61eYDgBKgAKe1lo%2BUs2TsDicaBcbl890eBjIMDKCAMlF8IKgQQCvG44Ky83sjkoAAkGTBaJJ6PkKWsqXAQj0oPQ%2BvSDIyQKpJAA2Mh6eiqbW68SKOW2BVqlWmtXuO2KUm0fBGk1mzBmFBgfCnbgIOh2DXG1W0PqI5G-dCAhRAA)

No repository file or test is named. Start with issue 11233 and compare the two linked Pyright Playground examples under strict mode; reproduce the inconsistent narrowing, then verify that the relevant attribute-access cases narrow consistently without regressing the contrasting scope behavior.

Written by the indexing model from the issue text.