gh-122622: Add sys._preexec hook for REPL by anthonykim1 · Pull Request #144724 · python/cpython

See issue mentioned for background info: #122622

Adding preexec hook will allow VS Code to enable shell integration for users on Windows! VS Code setting: python.terminal.shellIntegration.enabled

This also means we can also provide lsp completions in the REPL: https://code.visualstudio.com/updates/v1_101#_language-server-based-terminal-suggest

Also planning to enable PY_REPL back since #126131 is resolved.

Thank you

/cc @picnixz @Tyriar @brettcannon