fix(teams): omit group_id from Create/Update payload when empty

Only set GroupID in the API request when non-empty, consistent with
how description is handled. Sending an empty string pointer serializes
as "group_id": "" in the JSON payload which may cause unexpected
API behavior. Omitting the field (nil pointer with omitempty) is the
correct way to create a team without a group assignment.

Closes #56

Author: vmvarela

github/resource_github_enterprise_team.go

@@ -88,11 +88,13 @@ func resourceGithubEnterpriseTeamCreate(ctx context.Context, d *schema.ResourceD
 	req := github.EnterpriseTeamCreateOrUpdateRequest{
 		Name:                      name,
 		OrganizationSelectionType: github.Ptr(orgSelection),
-		GroupID:                   github.Ptr(groupID), // Empty string is valid for no group
 	}
 	if description != "" {
 		req.Description = github.Ptr(description)
 	}
+	if groupID != "" {
+		req.GroupID = github.Ptr(groupID)
+	}
 
 	ctx = context.WithValue(ctx, ctxId, d.Id())
 	te, _, err := client.Enterprise.CreateTeam(ctx, enterpriseSlug, req)
@@ -210,11 +212,13 @@ func resourceGithubEnterpriseTeamUpdate(ctx context.Context, d *schema.ResourceD
 	req := github.EnterpriseTeamCreateOrUpdateRequest{
 		Name:                      name,
 		OrganizationSelectionType: github.Ptr(orgSelection),
-		GroupID:                   github.Ptr(groupID), // Empty string clears the group
 	}
 	if description != "" {
 		req.Description = github.Ptr(description)
 	}
+	if groupID != "" {
+		req.GroupID = github.Ptr(groupID)
+	}
 
 	ctx = context.WithValue(ctx, ctxId, d.Id())
 	te, _, err := client.Enterprise.UpdateTeam(ctx, enterpriseSlug, teamSlug, req)