terraform-lambda-ecr-integration: Update AWS Provider to v6

[kakakakakku]

Issue #, if available:
N/A

Description of changes:
Hi😀 Thanks for the useful patterns!

To keep this pattern maintainable, I updated the AWS Provider to v6 and replaced deprecated HCL code. Also added --provenance=false to docker build for compatibility with newer Docker Desktop.

Check

terraform apply completed successfully and works good.

$ aws lambda invoke \
    --function-name testing-serverlessland-ecr-lambda \
    --cli-binary-format raw-in-base64-out \
    --log-type Tail --query 'LogResult' --output text --region us-east-1 \
    response.json | base64 --decode
START RequestId: d8dfae9d-2056-4d07-9f51-3cea5607d4bd Version: $LATEST
2026-05-02 08:02:10,082 : INFO : Lambda Function Started.
2026-05-02 08:02:10,082 : INFO : 
2026-05-02 08:02:10,082 : INFO : Sending Control to Shell Script...
hello world from the shell script in testing environment for serverlessland Org
Executing ls command at : Sat May  2 08:02:10 UTC 2026
total 2
-rwxr-xr-x 1 root root 794 Jul  5  2025 app.py
-rwxr-xr-x 1 root root 163 Jul  5  2025 sample-bash.sh
2026-05-02 08:02:10,207 : INFO : ...Control is back in Python
2026-05-02 08:02:10,207 : INFO : 
2026-05-02 08:02:10,207 : INFO : Lambda Function Finished.
END RequestId: d8dfae9d-2056-4d07-9f51-3cea5607d4bd
REPORT RequestId: d8dfae9d-2056-4d07-9f51-3cea5607d4bd  Duration: 131.54 ms     Billed Duration: 952 ms Memory Size: 512 MB     Max Memory Used: 38 MB  Init Duration: 820.09 ms

Thank you😀

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[kakakakakku]

╷
│ Error: creating Lambda Function (testing-serverlessland-ecr-lambda): operation error Lambda: CreateFunction, https response error StatusCode: 400, RequestID: 337794b6-72f5-4311-804b-a607af78a1ae, InvalidParameterValueException: The image manifest, config or layer media type for the source image 000000000000.dkr.ecr.us-east-1.amazonaws.com/testing-serverlessland-ecr-lambda@sha256:c548298ac414e9880c90c95b21be156f3a1dda1c6c86ef7882db9e9474a0952c is not supported.
│ 
│   with aws_lambda_function.this_aws_lambda_function,
│   on main.tf line 186, in resource "aws_lambda_function" "this_aws_lambda_function":
│  186: resource "aws_lambda_function" "this_aws_lambda_function" {
│ 
╵

[kakakakakku]

  ╷                                                                                                                                                                                 
  │ Warning: Deprecated attribute                                                                                                                                                   
  │                                                                                                                                                                                 
  │   on main.tf line 17, in locals:                                                                                                                                                
  │   17:   region                 = data.aws_region.current.name                                                                                                                   
  │                                                                                                                                                                                 
  │ The attribute "name" is deprecated. Refer to the provider documentation for details.