update prometheus dependencies (#5520)

Signed-off-by: junot <junotxiang@kubesphere.io>

vendor/github.com/go-openapi/spec/spec.go

@@ -14,7 +14,9 @@
 
 package spec
 
-import "encoding/json"
+import (
+	"encoding/json"
+)
 
 //go:generate curl -L --progress -o ./schemas/v2/schema.json http://swagger.io/v2/schema.json
 //go:generate curl -L --progress  -o ./schemas/jsonschema-draft-04.json http://json-schema.org/draft-04/schema
@@ -28,16 +30,6 @@ const (
 	JSONSchemaURL = "http://json-schema.org/draft-04/schema#"
 )
 
-var (
-	jsonSchema    *Schema
-	swaggerSchema *Schema
-)
-
-func init() {
-	jsonSchema = MustLoadJSONSchemaDraft04()
-	swaggerSchema = MustLoadSwagger20Schema()
-}
-
 // MustLoadJSONSchemaDraft04 panics when Swagger20Schema returns an error
 func MustLoadJSONSchemaDraft04() *Schema {
 	d, e := JSONSchemaDraft04()