Unable to find related issue for PR number 4314. Body details: "## Summary\r\n\r\nThis PR refactors the Idempotency utility to replace the `EnvironmentVariablesService` class-based approach with functional helper utilities from the commons package. The changes eliminate class inheritance and instantiation in favor of direct function calls, improving performance, reducing bundle size, and increasing consistency across the Powertools codebase.\r\n\r\n### Changes\r\n\r\n- **IdempotencyConfig**: Replaced `EnvironmentVariablesService` instantiation with direct `getBooleanFromEnv()` call for `POWERTOOLS_IDEMPOTENCY_DISABLED` environment variable\r\n- **BasePersistenceLayer**: Replaced `EnvironmentVariablesService` usage with direct `getStringFromEnv()` call for `AWS_LAMBDA_FUNCTION_NAME` environment variable\r\n- **Security Enhancement**: Implemented true runtime-private methods using `#` private field syntax\r\n- **Code Cleanup**: Removed unused `EnvironmentVariablesService.ts` and associated test files\r\n\r\n**Related Work:** This continues the architectural modernization started in #4251 (Logger utility), applying the same functional pattern to the Idempotency utility as part of the broader initiative to eliminate class-based environment services across all Powertools packages.\r\n\r\nIssue number: closes #4246 & #4247\r\n\r\n<!-------\r\nBefore creating the pull request, please make sure you do the following:\r\n\r\n- Read the Contributing Guidelines at https://github.com/aws-powertools/powertools-lambda-typescript/blob/main/CONTRIBUTING.md#sending-a-pull-request\r\n- Check that there isn't already a PR that addresses the same issue. If you find a duplicate, please leave a comment under the existing PR so we can discuss how to move forward\r\n- Check that the change meets the project's tenets https://docs.powertools.aws.dev/lambda/typescript/latest/#tenets\r\n- Add a PR title that follows the conventional commit semantics - https://github.com/aws-powertools/powertools-lambda-typescript/blob/main/.github/semantic.yml#L2\r\n- If relevant, add tests that prove that the change is effective and works\r\n- Whenever relevant, make sure to comment functions/methods/types and make appropriate changes to the documentation\r\n------->\r\n\r\n---\r\n\r\nBy submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.\r\n\r\n**Disclaimer**: We value your time and bandwidth. As such, any pull requests created on non-triaged issues might not be successful.\r\n"