resource/aws_redshift_snapshot_copy_grant: Fixes for tfproviderlint R006 (#12045)
resource/aws_redshift_snapshot_copy_grant: Fixes for tfproviderlint R006 (#12045)

Reference: https://github.com/terraform-providers/terraform-provider-aws/issues/11864

`RetryFunc` should only be used when logic has a retryable condition. In the case of working with the AWS Go SDK, it also arbitrarily restricts the automatic retrying logic of API calls to the timeout, which is generally undesired.

Previously:

```
aws/resource_aws_redshift_snapshot_copy_grant.go:274:38: R006: RetryFunc should include RetryableError() handling or be removed
```

Output from acceptance testing:

```
--- PASS: TestAccAWSRedshiftSnapshotCopyGrant_Basic (15.81s)
--- PASS: TestAccAWSRedshiftSnapshotCopyGrant_Update (38.59s)
```
terraform-providers/terraform-provider-aws,terraform-providers/terraform-provider-aws,terraform-providers/terraform-provider-aws,kjmkznr/terraform-provider-aws,kjmkznr/terraform-provider-aws,kjmkznr/terraform-provider-aws,kjmkznr/terraform-provider-aws,terraform-providers/terraform-provider-aws