SNS `delete_endpoint` is not idempotent

[Diego Hurtado de Mendoza]

The AWS documentation states that delete_endpoint is idempotent. However, moto raises a NotFoundException when attempting to delete an endpoint that was already deleted.

Example code:

client = boto3.client("sns")

platform_application_arn = client.create_platform_application(
    Name="test",
    Platform="GCM",
    Attributes={},
)["PlatformApplicationArn"]

token = "test-token"
endpoint_arn = client.create_platform_endpoint(
    PlatformApplicationArn=platform_application_arn,
    Token=token,
)["EndpointArn"]

client.delete_endpoint(EndpointArn=endpoint_arn)  # Works as expected

client.delete_endpoint(EndpointArn=endpoint_arn)  # Raises NotFoundException

Expected result: The last call to delete_endpoint should not raise an exception

Moto version: 5.0.3

[Bert Blommers]

Hi @DiegoHDMGZ, thanks for raising this - I'll open a PR with a fix.