chore: update golangci-lint to v2.13.0

Migrate the deprecated gofumpt `extra-rules` to `extra.group-params`, as
the alias now also enables the new `clothe-returns` and `balance-calls`
rules. Disable SA4023, which hangs on go 1.27, see
https://github.com/golangci/golangci-lint/issues/6732.

Apply the resulting modernize fixes, mostly flattening embedded struct
literals and switching errors.As to errors.AsType.

Assisted-by: Claude:Opus 5

services/attachment/attachment.go

@@ -10,6 +10,7 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"uuid"
 
 	"gitea.dev/models/db"
 	repo_model "gitea.dev/models/repo"
@@ -17,8 +18,6 @@ import (
 	"gitea.dev/modules/storage"
 	"gitea.dev/modules/util"
 	"gitea.dev/services/context/upload"
-
-	"uuid"
 )
 
 // NewAttachment creates a new attachment object, but do not verify.
@@ -85,8 +84,7 @@ func uploadAttachment(ctx context.Context, file *UploaderFile, allowedTypes stri
 	}
 
 	attach, err := NewAttachment(ctx, attach, io.MultiReader(bytes.NewReader(buf), src), file.size)
-	var maxBytesError *http.MaxBytesError
-	if errors.As(err, &maxBytesError) {
+	if _, ok := errors.AsType[*http.MaxBytesError](err); ok {
 		return nil, util.ErrorWrap(util.ErrContentTooLarge, "attachment exceeds limit %d", maxFileSize)
 	}
 	return attach, err