chore(yaml): upgrade dependency to v3 version (#3456)

fixes https://github.com/gin-gonic/gin/issues/3451
fixes https://github.com/gin-gonic/gin/issues/3306
fixes https://github.com/gin-gonic/gin/issues/3362
fixes https://github.com/gin-gonic/gin/issues/2581

render/render_test.go

@@ -238,7 +238,7 @@ b:
 
 	err := (YAML{data}).Render(w)
 	assert.NoError(t, err)
-	assert.Equal(t, "\"\\na : Easy!\\nb:\\n\\tc: 2\\n\\td: [3, 4]\\n\\t\"\n", w.Body.String())
+	assert.Equal(t, "|4-\n    a : Easy!\n    b:\n    \tc: 2\n    \td: [3, 4]\n    \t\n", w.Body.String())
 	assert.Equal(t, "application/x-yaml; charset=utf-8", w.Header().Get("Content-Type"))
 }
 

render/yaml.go

@@ -7,7 +7,7 @@ package render
 import (
 	"net/http"
 
-	"gopkg.in/yaml.v2"
+	"gopkg.in/yaml.v3"
 )
 
 // YAML contains the given interface object.