[Website]: SQL Input Plugin for Elasticsearch - Oracle Driver / Library prerequisite

### Before you submit

- [x] This issue is about a documentation page, flow, or piece of content.

### Type of issue

Missing information

### What documentation page or section is affected

https://www.elastic.co/docs/reference/integrations/sql

### What happened?

The SQL Plugin for Elasticsearch documentation page should mention that for _Oracle specifically_, users must make sure to have the correct `libclntsh.so` Oracle client library for linux installed on the host machine. While the Microsoft SQL driver is typically self-contained and works without special configuration, for Oracle, you need to install these external native libraries (`libclntsh.so`) on the host operating system where the Elastic Agent is running.