Make the "Ingest logs from a Python application using Filebeat” guide deployment-agnostic

[vishaangelova]

In #1640, we updated the Ingest logs from a Python application using Filebeat guide to remove outdated info and to create a more logical structure. During the PR review, it came up that we should probably make this guide deployment-agnostic for it to fit better in the new IA.

Investigate, and if possible, adapt the guide to be more generic with regard to the deployment type used. Currently, the workflow is based on ECH.

The steps described in the guide should be mostly valid (or may need to be adapted just slightly) to send data to a self-managed, ECK or ECE managed cluster, and may also be valid for Serverless. The latter might require a bit more investigation as, in Serverless, we rely on API keys for authentication and not user credentials anymore.

cc: @eedugon @shainaraskas

[shainaraskas]

imo this is an ingest team issue which we can support, not an admin docs team issue.