feat: add github_organization_invitation resource

[nitinjain999]

Closes #2197

Picking up the work from #3229 (original author inactive) and addressing all maintainer review feedback.

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Before the change?

github_membership only works when a user already has a GitHub account and is identified by their username. There was no way to invite someone to an org by email address, which is a common need when onboarding new users who may not yet have GitHub accounts.

After the change?

New resource github_organization_invitation:

# Invite by email
resource "github_organization_invitation" "example" {
  email = "newmember@example.com"
  role  = "direct_member"
}

# Invite by GitHub user ID
data "github_user" "invitee" {
  username = "someuser"
}

resource "github_organization_invitation" "example" {
  invitee_id = data.github_user.invitee.id
}

Changes vs #3229

All three issues flagged by @deiga are addressed, plus one additional bug found during testing:

1. Redundant invitation_id computed field removed — the resource ID already is the invitation ID
2. ctx = context.WithValue(ctx, ctxId, ...) removed from Read and Delete — not needed
3. Idempotency fixed — when an invitation is no longer in the pending list, Read now checks whether the invitee accepted and became an org member via IsMember. If they are a member, the resource stays in state. Only if the invitee is neither pending nor a member (expired/cancelled) is the resource removed from state
4. Email drift bug fixed — the GitHub API always returns the invitee's email in the invitation response, even for invitee_id-based invitations. The original PR set email from the API response unconditionally, which caused a perpetual destroy/recreate diff when invitee_id was the configured field. Now email is only written to state when the resource was created with email

Testing

invite_by_invitee_id PASSES verified against a real org (nitin-sv) with deiga as the external user.

invite_by_email and invite_with_admin_role skip when GH_TEST_INVITATION_EMAIL is not set — they require an email address not already associated with an org member.

Pull request checklist

• Schema migrations have been created if needed — not applicable
• Tests for the changes have been added
• Docs have been reviewed and added / updated if needed

Does this introduce a breaking change?

• Yes
• No

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[github-actions]

👋 Hi, and thank you for this contribution!

This repo is maintained by GitHub and community members on a best-effort basis. We'll get to this as soon as we can.

You can help us prioritize by joining the discussion on open issues and PRs, sharing details on the changes you need, and reviewing other contributions.

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[janellecanon01-lab]

h

[nitinjain999]

what you mean by h ?