Python getting started: remove stale batch job doc link

[soxofaan]

remove deep link to batch job docs that became stale after rework of "getting started" doc https://open-eo.github.io/openeo-python-client/basics.html under Open-EO/openeo-python-client#308

[soxofaan]

side question: I somewhat remember that there is some kind of external link checker (test?) for the docs. But it probably only checks if the url returns with 2xx, not if the #-fragment is valid?

[m-mohr]

Yes, npm test, but for external links the fragments won't be checked, I think.