(reticulate) handle blank lines in python code chunks sent to `reticulate::repl_python`

[jmbuhr]

otherwise blank lines cause e.g. classes or methods to end prematurely. Need some form of bracketed paste.

[akthe-at]

will this be solved with the new repl that is coming in python 3.13?

[jmbuhr]

No, the issue is in a different place, but that's still a thing to look out for in the future, thanks for the heads up.