[Vendor] update go-swagger v0.21.0 -> v0.25.0 (#12670)

* Update go-swagger

* vendor

vendor/github.com/mailru/easyjson/unknown_fields.go

@@ -0,0 +1,34 @@
+package easyjson
+
+import (
+	json "encoding/json"
+
+	jlexer "github.com/mailru/easyjson/jlexer"
+	"github.com/mailru/easyjson/jwriter"
+)
+
+// UnknownFieldsProxy implemets UnknownsUnmarshaler and UnknownsMarshaler
+// use it as embedded field in your structure to parse and then serialize unknown struct fields
+type UnknownFieldsProxy struct {
+	unknownFields map[string]interface{}
+}
+
+func (s *UnknownFieldsProxy) UnmarshalUnknown(in *jlexer.Lexer, key string) {
+	if s.unknownFields == nil {
+		s.unknownFields = make(map[string]interface{}, 1)
+	}
+	s.unknownFields[key] = in.Interface()
+}
+
+func (s UnknownFieldsProxy) MarshalUnknowns(out *jwriter.Writer, first bool) {
+	for key, val := range s.unknownFields {
+		if first {
+			first = false
+		} else {
+			out.RawByte(',')
+		}
+		out.String(string(key))
+		out.RawByte(':')
+		out.Raw(json.Marshal(val))
+	}
+}