Use AWS Regionalized STS Endpoints

User Story:

As a ROSA customer, I want to enforce that my workloads follow AWS best-practices by using AWS Regionalized STS Endpoints instead of the global one.

As Red Hat, I would like to follow AWS best-practices by using AWS Regionalized STS Endpoints instead of the global one.

Per AWS docs:

https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_temp_enable-regions.html 

AWS recommends using Regional AWS STS endpoints instead of the global endpoint to reduce latency, build in redundancy, and increase session token validity. 

https://docs.aws.amazon.com/sdkref/latest/guide/feature-sts-regionalized-endpoints.html

All new SDK major versions releasing after July 2022 will default to regional. New SDK major versions might remove this setting and use regional behavior. To reduce future impact regarding this change, we recommend you start using regional in your application when possible. 

Acceptance Criteria:

Areas where HyperShift creates STS credentials use regionalized STS endpoints, e.g. https://github.com/openshift/hypershift/blob/ae1caa00ff3a2c2bfc1129f0168efc1e786d1d12/control-plane-operator/hostedclusterconfigoperator/controllers/resources/resources.go#L1225-L1228 

Engineering Details:

• https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_temp_enable-regions.html 
• https://docs.aws.amazon.com/sdkref/latest/guide/feature-sts-regionalized-endpoints.html
• This was done in ROSA Classic via SDA-7313