docs: Deprecate old Copilot metrics endpoints closed on April 2, 2026 (#4137)

Author: Bahtya

github/copilot.go

@@ -491,6 +491,10 @@ func (s *CopilotService) GetSeatDetails(ctx context.Context, org, user string) (
 
 // GetEnterpriseMetrics gets Copilot usage metrics for an enterprise.
 //
+// Deprecated: This endpoint was closed down on April 2, 2026 for github.com.
+// It may still be available for GitHub Enterprise Server. Use GetEnterpriseDailyMetricsReport
+// or GetEnterpriseMetricsReport instead.
+//
 // GitHub API docs: https://docs.github.com/enterprise-cloud@latest/rest/copilot/copilot-metrics#get-copilot-metrics-for-an-enterprise
 //
 //meta:operation GET /enterprises/{enterprise}/copilot/metrics
@@ -517,6 +521,10 @@ func (s *CopilotService) GetEnterpriseMetrics(ctx context.Context, enterprise st
 
 // GetEnterpriseTeamMetrics gets Copilot usage metrics for an enterprise team.
 //
+// Deprecated: This endpoint was closed down on April 2, 2026 for github.com.
+// It may still be available for GitHub Enterprise Server. Use GetEnterpriseDailyMetricsReport
+// or GetEnterpriseMetricsReport instead.
+//
 // GitHub API docs: https://docs.github.com/enterprise-cloud@latest/rest/copilot/copilot-metrics#get-copilot-metrics-for-an-enterprise-team
 //
 //meta:operation GET /enterprises/{enterprise}/team/{team_slug}/copilot/metrics
@@ -543,6 +551,10 @@ func (s *CopilotService) GetEnterpriseTeamMetrics(ctx context.Context, enterpris
 
 // GetOrganizationMetrics gets Copilot usage metrics for an organization.
 //
+// Deprecated: This endpoint was closed down on April 2, 2026 for github.com.
+// It may still be available for GitHub Enterprise Server. Use GetOrganizationDailyMetricsReport
+// or GetOrganizationMetricsReport instead.
+//
 // GitHub API docs: https://docs.github.com/rest/copilot/copilot-metrics#get-copilot-metrics-for-an-organization
 //
 //meta:operation GET /orgs/{org}/copilot/metrics
@@ -569,6 +581,10 @@ func (s *CopilotService) GetOrganizationMetrics(ctx context.Context, org string,
 
 // GetOrganizationTeamMetrics gets Copilot usage metrics for an organization team.
 //
+// Deprecated: This endpoint was closed down on April 2, 2026 for github.com.
+// It may still be available for GitHub Enterprise Server. Use GetOrganizationDailyMetricsReport
+// or GetOrganizationMetricsReport instead.
+//
 // GitHub API docs: https://docs.github.com/rest/copilot/copilot-metrics#get-copilot-metrics-for-a-team
 //
 //meta:operation GET /orgs/{org}/team/{team_slug}/copilot/metrics