Fix region mismatch in pytorch example

[raykrueger]

What does this PR do?

The Ray on EKS module deploys to us-west-2, the example application attempts to target us-east-1.

This commit moves the region to variables and corrects the mismatch.

Motivation

Fixing it :)

More

• Yes, I have tested the PR using my local account setup (Provide any test evidence report under Additional Notes)
• Mandatory for new blueprints. Yes, I have added a example to support my blueprint PR
• Mandatory for new blueprints. Yes, I have updated the website/docs or website/blog section for this feature
• Yes, I ran pre-commit run -a with this PR. Link for installing pre-commit locally

For Moderators

• E2E Test successfully complete before merge?

Additional Notes