Remove required arguments from updateIssue mutation

Remove required statement from due_date and confidential arguments

app/graphql/mutations/issues/update.rb

@@ -17,12 +17,12 @@ module Mutations
 
       argument :due_date,
                Types::TimeType,
-               required: true,
+               required: false,
                description: copy_field_description(Types::IssueType, :due_date)
 
       argument :confidential,
                GraphQL::BOOLEAN_TYPE,
-               required: true,
+               required: false,
                description: copy_field_description(Types::IssueType, :confidential)
 
       def resolve(project_path:, iid:, **args)

doc/api/graphql/reference/gitlab_schema.graphql

@@ -7925,7 +7925,7 @@ input UpdateIssueInput {
   """
   Indicates the issue is confidential
   """
-  confidential: Boolean!
+  confidential: Boolean
 
   """
   Description of the issue
@@ -7935,7 +7935,7 @@ input UpdateIssueInput {
   """
   Due date of the issue
   """
-  dueDate: Time!
+  dueDate: Time
 
   """
   The desired health status

doc/api/graphql/reference/gitlab_schema.json

@@ -20850,13 +20850,9 @@
               "name": "dueDate",
               "description": "Due date of the issue",
               "type": {
-                "kind": "NON_NULL",
-                "name": null,
-                "ofType": {
-                  "kind": "SCALAR",
-                  "name": "Time",
-                  "ofType": null
-                }
+                "kind": "SCALAR",
+                "name": "Time",
+                "ofType": null
               },
               "defaultValue": null
             },
@@ -20864,13 +20860,9 @@
               "name": "confidential",
               "description": "Indicates the issue is confidential",
               "type": {
-                "kind": "NON_NULL",
-                "name": null,
-                "ofType": {
-                  "kind": "SCALAR",
-                  "name": "Boolean",
-                  "ofType": null
-                }
+                "kind": "SCALAR",
+                "name": "Boolean",
+                "ofType": null
               },
               "defaultValue": null
             },