Make the AWS region configurable

[edgarrmondragon]

Is your feature request related to a problem? Please describe.

Currently eu-west-1 is hard-coded in this target, it'd be nice (and necessary for some folks) to make it configurable.

target-redshift/target_redshift/sinks.py

Lines 31 to 35 in c483ee2

	class RedshiftSink(SQLSink):
	"""Redshift target sink class."""
	connector_class = RedshiftConnector
	s3_client = boto3.client("s3", region_name="eu-west-1")

target-redshift/target_redshift/connector.py

Lines 503 to 512 in c483ee2

	def get_credentials(self) -> tuple[str, str]:
	"""Use boto3 to get temporary cluster credentials
	Returns
	-------
	tuple[str, str]
	username and password
	"""
	if self.config.get("enable_iam_authentication"):
	client = boto3.client("redshift", region_name="eu-west-1")

Describe the solution you'd like

Add a new setting aws_region, which defaults to "eu-west-1".

Describe alternatives you've considered

Nothing so far.

Additional context

• https://meltano.slack.com/archives/C069A0GE129/p1722832582189159
• https://www.linen.dev/s/meltano/t/22876728/is-meltano-going-to-develop-a-meltanolabs-redshift-connector#9fbdef70-45ec-47d1-9f00-3babc14f37e7