DOCS: Release process needs tip on how to find latest version (#4007)

<!--
## Before submiting a pull request

Please make sure you've run the following commands from the root
directory.

    bin/generate-all.sh

(this runs commands like "go generate", fixes formatting, and so on)

## Release changelog section

Help keep the release changelog clear by pre-naming the proper section
in the GitHub pull request title.

Some examples:
* CICD: Add required GHA permissions for goreleaser
* DOCS: Fixed providers with "contributor support" table
* ROUTE53: Allow R53_ALIAS records to enable target health evaluation

More examples/context can be found in the file .goreleaser.yml under the
'build' > 'changelog' key.
!-->

Author: tlimoncelli

documentation/release/release-engineering.md

@@ -32,8 +32,10 @@ git commit -am "CHORE: generate-all.sh"
 ## Step 2. Tag the commit in main that you want to release
 
 ```shell
+git tag -l |grep -F v4. | sort --version-sort --field-separator=. --key=2,2 | tail
 export VERSION=v4.x.0
 git checkout main
+git pull --rebase --ff-only --prune
 git tag -m "Release $VERSION" -a $VERSION
 git push origin HEAD --tags
 ```