[BUG]: Support suspended EMU users

Expected Behavior

Able to remove a suspended GitHub EMU user from a team or repository.

Actual Behavior

The user cannot be found because when a user is suspend its username goes from {normalized_idp_username}_{enterprise_shortcode} to an obfuscated hash: {username_hash}_{enterprise_shortcode}

See https://docs.github.com/en/enterprise-cloud@latest/admin/managing-iam/provisioning-user-accounts-with-scim/deprovisioning-and-reinstating-users#effects-of-soft-deprovisioning

All username based operations will fail on suspended users or silently fail.

Terraform Version

v6.12.1

It was happening for a long time any way

Affected Resource(s)

• resource_github_team_members
• but also all other resources referencing a user by username

Terraform Configuration Files

Steps to Reproduce

Get a EMU account
Create a team and add the EMU user as a member
Suspend the user and wait for the username change
Try to remove the user

Debug Output

Panic Output

Code of Conduct

• I agree to follow this project's Code of Conduct

Start with the resource_github_team_members entry point and trace how username-based operations identify users through the GitHub API. Compare behavior before and after an EMU user is suspended, then check other resources that reference users by username. Done means suspended EMU users can be removed and username-based operations no longer fail or silently do nothing.