Added swagger model definition for deadline response

public/swagger.v1.json

@@ -6556,6 +6556,18 @@
       },
       "x-go-package": "code.gitea.io/gitea/vendor/code.gitea.io/sdk/gitea"
     },
+    "IssueDeadline": {
+      "description": "IssueDeadline represents an issue deadline",
+      "type": "object",
+      "properties": {
+        "due_date": {
+          "type": "string",
+          "format": "date-time",
+          "x-go-name": "Deadline"
+        }
+      },
+      "x-go-package": "code.gitea.io/gitea/vendor/code.gitea.io/sdk/gitea"
+    },
     "IssueLabelsOption": {
       "description": "IssueLabelsOption a collection of labels",
       "type": "object",
@@ -7533,6 +7545,11 @@
         "$ref": "#/definitions/Issue"
       }
     },
+    "IssueDeadline": {
+      "schema": {
+        "$ref": "#/definitions/IssueDeadline"
+      }
+    },
     "IssueList": {
       "schema": {
         "type": "array",

routers/api/v1/swagger/issue.go

@@ -67,3 +67,9 @@ type swaggerResponseTrackedTimeList struct {
 	// in:body
 	Body []api.TrackedTime `json:"body"`
 }
+
+// swagger:response IssueDeadline
+type swaggerIssueDeadline struct {
+	// in:body
+	Body api.IssueDeadline `json:"body"`
+}