feat: Ensure compatibility with encoding/json/v2 experiment (#4029)

Author: munlicode

github/github_test.go

@@ -572,16 +572,13 @@ func TestNewRequest_invalidJSON(t *testing.T) {
 	c := NewClient(nil)
 
 	type T struct {
-		A map[any]any
+		F func()
 	}
 	_, err := c.NewRequest("GET", ".", &T{})
 
 	if err == nil {
 		t.Error("Expected error to be returned.")
 	}
-	if !errors.As(err, new(*json.UnsupportedTypeError)) {
-		t.Errorf("Expected a JSON error; got %#v.", err)
-	}
 }
 
 func TestNewRequest_badURL(t *testing.T) {

github/repos_hooks_deliveries_test.go

@@ -9,6 +9,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"strings"
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
@@ -261,7 +262,7 @@ func TestHookDelivery_ParsePayload_invalidPayload(t *testing.T) {
 	}
 
 	_, err := d.ParseRequestPayload()
-	if err == nil || err.Error() != "json: cannot unmarshal string into Go struct field CheckRun.check_run.id of type int64" {
+	if err == nil || !strings.Contains(err.Error(), "json: cannot unmarshal") || !strings.Contains(err.Error(), "check_run.id") {
 		t.Errorf("unexpected error: %v", err)
 	}
 }

github/security_advisories_test.go

@@ -590,7 +590,7 @@ func TestSecurityAdvisoriesService_ListRepositorySecurityAdvisoriesForOrg_Unmars
 	advisories, resp, err := client.SecurityAdvisories.ListRepositorySecurityAdvisoriesForOrg(ctx, "o", nil)
 	if err == nil {
 		t.Error("Expected unmarshal error")
-	} else if !strings.Contains(err.Error(), "json: cannot unmarshal number into Go struct field SecurityAdvisory.ghsa_id of type string") {
+	} else if !strings.Contains(err.Error(), "json: cannot unmarshal") || !strings.Contains(err.Error(), "ghsa_id") {
 		t.Errorf("ListRepositorySecurityAdvisoriesForOrg returned unexpected error: %v", err)
 	}
 	if got, want := resp.Response.StatusCode, http.StatusOK; got != want {
@@ -721,7 +721,7 @@ func TestSecurityAdvisoriesService_ListRepositorySecurityAdvisories_UnmarshalErr
 	advisories, resp, err := client.SecurityAdvisories.ListRepositorySecurityAdvisories(ctx, "o", "r", nil)
 	if err == nil {
 		t.Error("Expected unmarshal error")
-	} else if !strings.Contains(err.Error(), "json: cannot unmarshal number into Go struct field SecurityAdvisory.ghsa_id of type string") {
+	} else if !strings.Contains(err.Error(), "json: cannot unmarshal") || !strings.Contains(err.Error(), "ghsa_id") {
 		t.Errorf("ListRepositorySecurityAdvisories returned unexpected error: %v", err)
 	}
 	if got, want := resp.Response.StatusCode, http.StatusOK; got != want {