chore: Updated code owners

[Prekshith-Microsoft]

This pull request makes a minor update to the repository's code ownership configuration by adding two new default owners.

• .github/CODEOWNERS: Added @toherman-msft and @nchandhi as default owners for the entire repository.## Purpose

• ...

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