AWS SDK V2 Upgrade and update scalers

[jeevanragula]

In the Keda project, we are currently using below AWS Go SDK version.

github.com/aws/aws-sdk-go v1.44.287

But AWS released a V2 version long back which has few advantages over V1.
This PR is to update the code to use AWS SDK V2.

Checklist

• When introducing a new scaler, I agree with the scaling governance policy
• I have verified that my change is according to the deprecations & breaking changes policy
• Tests have been added
• Changelog has been updated and is aligned with our changelog requirements
• A PR is opened to update our Helm chart (repo) (if applicable, ie. when deployment manifests are modified)
• A PR is opened to update the documentation on (repo) (if applicable)
• Commits are signed with Developer Certificate of Origin (DCO - learn more)

Fixes #4905

Relates to #4905

[github-actions]

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[JorTurFer]

LGTM! Thanks for the contribution 🙇

[JorTurFer]

/run-e2e aws
Update: You can check the progress here

[JorTurFer]

/run-e2e aws
Update: You can check the progress here

[zroubalik]

LGTM, thanks!