refactor: make principal type optional in role assignments and clean up e2e tests

[Harmanpreet-Microsoft]

Purpose

This pull request introduces improvements to the role assignment module in the infrastructure code, making principal type detection more flexible and simplifying usage in main deployment scripts. It also includes minor cleanups in the end-to-end test scripts for better readability.

Infrastructure improvements:

• Updated core/security/role.bicep to allow automatic principal type detection by making principalType optional and including it only if explicitly provided. This enables more flexible role assignments for different principal types.
• Commented out explicit principalType: 'User' assignments in the main infrastructure deployment (infra/main.bicep), so principal type is now auto-detected unless specifically set. This reduces redundancy and potential errors. [1] [2] [3]

Test script cleanups:

• Removed duplicate import statements and improved code formatting in tests/e2e-test/tests/test_chat_with_your_data.py for better readability.
• Cleaned up step function definitions in the same test file by removing duplicate code and improving structure. [1] [2]
• ...

Does this introduce a breaking change?

• Yes
• No

How to Test

• Get the code

git clone [repo-address]
cd [repo-name]
git checkout [branch-name]
npm install

• Test the code

What to Check

Verify that the following are valid

• ...

Other Information