chore(enterprise-teams): move listAllEnterpriseTeamOrganizations to util_enterprise_teams.go

[vmvarela]

Description

Reviewer question: should listAllEnterpriseTeamOrganizations be in util_enterprise_teams.go instead of being defined inside the data source? Yes — shared pagination helpers belong in util_enterprise_teams.go.

Acceptance Criteria

• Move listAllEnterpriseTeamOrganizations from data_source_github_enterprise_team_organizations.go (or wherever it lives) to util_enterprise_teams.go
• Update all callers accordingly
• Verify make build passes

Notes

Upstream PR: integrations#3008