fix: remove AWS_DEFAULT_REGION

[Flydiverny]

Not sure why AWS_DEFAULT_REGION was added in the first place, but it seems misleading to have. Its not provided in the docs everywhere and the AWS SDK for JS uses AWS_REGION so the AWS_DEFAULT_REGION should not be used, if one uses the aws cli it does seem to prefer AWS_DEFAULT_REGION though in some cases 😄

[moolen]

That makes sense, this is a big inconsistency in the aws sdks.

[arischow]

@Flydiverny

I think after this change, there should be a new Helm chart version release? Well I am new to this repo but I have to say after installing this chart, this environment variable did confuse me, especially I specified the region (AWS_REGION) to another one.

[Flydiverny]

@arischow should be a new release cut now :)