docs: fix copy doctests without `>>>` and `...` by button & ctr+c (#2138)

* Add custom JavaScript for copying Python REPL code examples without prompts and integrate it into the docs
* Enhance JavaScript copy button functionality to support `.md-code__button` and streamline clipboard handling
* Remove unused `pycon_copy.js` references and streamline JavaScript dependencies in docs and configuration
* Enhance `stripPythonPrompts` to handle triple-quoted strings in REPL code parsing

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Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>