chore: remove unused extensions from Gitpod/CodeSpaces

[niko-achilles]

Description of your changes

Removed tslint-plugin from gitpod definition and devcontainer definition.

• ms-vscode.vscode-typescript-tslint-plugin

TSLint has been deprecated in favor of ESLint and the extension has also been deprecated in favor of ESLint's tooling.

How to verify this change

ms-vscode.vscode-typescript-tslint-plugin is excluded by deleting it from gitpod.ym and devcontainer.json artifacts:

• gitpod: https://github.com/awslabs/aws-lambda-powertools-typescript/blob/main/.gitpod.yml
• devcontainer: https://github.com/awslabs/aws-lambda-powertools-typescript/blob/main/.devcontainer/devcontainer.json

Related issues, RFCs

Issue number: #1276

PR status

Is this ready for review?: YES
Is it a breaking change?: NO

Checklist

• My changes meet the tenets criteria
• I have performed a self-review of my own code
• I have commented my code where necessary, particularly in areas that should be flagged with a TODO, or hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding changes to the examples
• My changes generate no new warnings
• The code coverage hasn't decreased
• I have added tests that prove my change is effective and works
• New and existing unit tests pass locally and in Github Actions
• Any dependent changes have been merged and published
• The PR title follows the conventional commit semantics

Breaking change checklist

• I have documented the migration process
• I have added, implemented necessary warnings (if it can live side by side)

---

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[dreamorosi]

Thank you for opening this PR Niko, looks good to me