Execution model reference should cover `closure` arg to `exec` & `eval`

When the closure parameter was added to exec and eval for Python 3.11, it rendered the "Interaction with dynamic features" part of the execution model reference slightly out of date: https://docs.python.org/3/reference/executionmodel.html#interaction-with-dynamic-features

The text remains accurate for string execution, but needs updating to correctly cover execution of code objects with closure variable references.

Linked PRs

• gh-155014

从 issue 中链接的执行模型参考文档的“Interaction with dynamic features”部分开始，并查看链接的 PR gh-155014 以了解已有工作。更新该参考文档，使其对于字符串执行仍然准确，同时也涵盖通过 exec 和 eval 传递的、包含闭包变量引用的代码对象。