Website states that 3.0 is still not released

## Description

https://awspring.io/learn/introduction/ states that 3.0.0 is still not released and links to the snapshot version.

### Steps to reproduce

Navigate to https://awspring.io/learn/introduction/.

### Expected result

Refer to the latest 3.0 release and its documentation.

### Actual result

Snapshot versions.

### Environment

n/a
