Upgrade to golangci-lint v2 (#1008)

toml_testgen_support_test.go

@@ -1,11 +1,11 @@
 //go:generate go run github.com/toml-lang/toml-test/cmd/toml-test@v1.6.0 -copy ./tests
 //go:generate go run ./cmd/tomltestgen/main.go -r v1.6.0 -o toml_testgen_test.go
 
-// This is a support file for toml_testgen_test.go
 package toml_test
 
 import (
 	"encoding/json"
+	"errors"
 	"testing"
 
 	"github.com/pelletier/go-toml/v2"
@@ -39,7 +39,8 @@ func testgenValid(t *testing.T, input string, jsonRef string) {
 
 	err := testsuite.Unmarshal([]byte(input), &doc)
 	if err != nil {
-		if de, ok := err.(*toml.DecodeError); ok {
+		de := &toml.DecodeError{}
+		if errors.As(err, &de) {
 			t.Logf("%s\n%s", err, de)
 		}
 		t.Fatalf("failed parsing toml: %s", err)