Maintain major release tag for docker images

### Describe the feature

Please add a tag marking the latest major release of `aws-cli`. For example, if version `2.11.3` were released, tag `2` should be updated in dockerhub pointing to this same release.

### Use Case

I'd like to track the latest stable version of aws-cli v2. However, I do not want to start pulling v3 when it's released, thus tracking `aws-cli:latest` doesn't work for me.

### Proposed Solution

As described above, I propose simply adding a tag named `2` to the `aws-cli` dockerhub and updating this tag after every new release of aws-cli v2.

### Other Information

_No response_

### Acknowledgements

- [ ] I may be able to implement this feature request
- [ ] This feature might incur a breaking change

### CLI version used

2

### Environment details (OS name and version, etc.)

docker, kubernetes, linux