Fix type conversion error in polaris_aws_exocompute (#209)

During a prior refactoring, a new type was introduced for AWS regions
to handle cases where the same region has multiple representations in
the GraphQL API. This type was not properly converted in all code
paths.

internal/provider/resource_aws_exocompute.go

@@ -259,7 +259,7 @@ func awsReadExocompute(ctx context.Context, d *schema.ResourceData, m interface{
 			return diag.FromErr(err)
 		}
 
-		if err := d.Set(keyRegion, exoConfig.Region); err != nil {
+		if err := d.Set(keyRegion, exoConfig.Region.Name()); err != nil {
 			return diag.FromErr(err)
 		}
 
@@ -274,8 +274,8 @@ func awsReadExocompute(ctx context.Context, d *schema.ResourceData, m interface{
 			return diag.FromErr(err)
 		}
 		subnets := schema.Set{F: schema.HashString}
-		subnets.Add(exoConfig.Subnet1)
-		subnets.Add(exoConfig.Subnet2)
+		subnets.Add(exoConfig.Subnet1.ID)
+		subnets.Add(exoConfig.Subnet2.ID)
 		if err := d.Set(keySubnets, &subnets); err != nil {
 			return diag.FromErr(err)
 		}