Fix IAM User Policy No Such Entity Exception Handling

[teraken0509]

Changes proposed in this pull request:

• aws_iam_user_policy skip error when NoSuchEntity error occured while deleting.
• Add test case

Output from acceptance testing:

$ make testacc TEST=./aws TESTARGS='-run=TestAccAWSIAMUserPolicy_disappears'
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./aws -v -parallel 20 -run=TestAccAWSIAMUserPolicy_disappears -timeout 120m
=== RUN   TestAccAWSIAMUserPolicy_disappears
=== PAUSE TestAccAWSIAMUserPolicy_disappears
=== CONT  TestAccAWSIAMUserPolicy_disappears
--- PASS: TestAccAWSIAMUserPolicy_disappears (23.51s)
PASS
ok      github.com/terraform-providers/terraform-provider-aws/aws    23.570s

[bflad]

LGTM, thanks @kterada0509! 🚀

--- PASS: TestAccAWSIAMUserPolicy_disappears (7.19s)
--- PASS: TestAccAWSIAMUserPolicy_importBasic (8.26s)
--- PASS: TestAccAWSIAMUserPolicy_namePrefix (12.67s)
--- PASS: TestAccAWSIAMUserPolicy_generatedName (12.96s)
--- PASS: TestAccAWSIAMUserPolicy_basic (13.06s)
--- PASS: TestAccAWSIAMUserPolicy_multiplePolicies (23.48s)

[bflad]

This has been released in version 1.55.0 of the AWS provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

[ghost]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

If you feel this issue should be reopened, we encourage creating a new issue linking back to this one for added context. Thanks!