fix: Update package.py

[ArtPiece55]

install_pip_requirements: fixing --target section of pip install, following aws documentation (https://docs.aws.amazon.com/lambda/latest/dg/python-layers.html)

Description

Minor fix to pip requirements install path

Motivation and Context

Following AWS documentation regarding Working with layers for Python Lambda functions (https://docs.aws.amazon.com/lambda/latest/dg/python-layers.html), the --target of pip install must have Choose one of the following methods to install pip packages into the required top-level directory (python/):
Without the implemented fix, a test of the lambda function returns an error (Examples below).

Example module usage:

module "lambda_requests_layer" {
  source  = "terraform-aws-modules/lambda/aws"
  version = "7.21.0"

  create_layer = true

  layer_name          = "requests"
  runtime         = "python3.9"
  build_in_docker = true
  source_path = [{
    pip_tmp_dir      = "${path.module}/src/lambda/layer_tmp"
    pip_requirements = "${path.module}/src/lambda/requirements.txt"
  }]
  artifacts_dir = "${path.root}/.terraform/builds/${var.project_name}-requests"
}

module "lambda_fallback" {
  source  = "terraform-aws-modules/lambda/aws"
  version = "7.21.0"

  function_name           = "${var.project_name}-fallbacklambda"
  handler                 = "lambda_function_test.lambda_handler"
  runtime                 = "python3.9"
  source_path             = "${path.module}/src/lambda/lambda_function_test.py"
  layers = [module.lambda_requests_layer.lambda_layer_arn]
  publish                 = true
  ignore_source_code_hash = true
  attach_policies         = true
  number_of_policies      = 1
  policies = [
    "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
  ]
  artifacts_dir           = "${path.root}/.terraform/builds/${var.project_name}-fallbacklambda"
}

Example requirements:

requests==2.32.3

Example python code:

import requests

def lambda_handler(event, context):
   response = requests.get("https://httpbin.org/get", timeout=10)
   print(response.json())

Lambda function execution error:

[ERROR] Runtime.ImportModuleError: Unable to import module 'lambda_function_test': No module named 'requests'
Traceback (most recent call last):

Breaking Changes

How Has This Been Tested?

• I have updated at least one of the examples/* to demonstrate and validate my change(s)
• I have tested and validated these changes using one or more of the provided examples/* projects

• I have executed pre-commit run -a on my pull request

The master has been pulled, implemeted the proposed change, used new source module source = "../terraform-aws-lambda" on the previously described module usage, returned output:

Status: Succeeded
Test Event Name: TEST_EVENT

Response:
null

Function Logs:
START RequestId: 224fb8c9-8590-41e8-abff-8b995e23115d Version: $LATEST
{'args': {}, 'headers': {'Accept': '*/*', 'Accept-Encoding': 'gzip, deflate', 'Host': 'httpbin.org', 'User-Agent': 'python-requests/2.32.3', 'X-Amzn-Trace-Id': 'Root=1-6841ccba-632cc83457388d0c4fc43ba5'}, 'origin': '98.83.38.2', 'url': 'https://httpbin.org/get'}
END RequestId: 224fb8c9-8590-41e8-abff-8b995e23115d
REPORT RequestId: 224fb8c9-8590-41e8-abff-8b995e23115d	Duration: 8978.87 ms	Billed Duration: 8979 ms	Memory Size: 128 MB	Max Memory Used: 53 MB	Init Duration: 355.96 ms

Request ID: 224fb8c9-8590-41e8-abff-8b995e23115d