chore: remove nullable

Author: shanewxy

schema.yaml

@@ -21,7 +21,6 @@ components:
               default: cluster.local
               description: |
                 Specify the domain name for discovering the service.
-              nullable: true
               title: Domain Suffix
               type: string
               x-walrus-ui:
@@ -47,7 +46,6 @@ components:
           enum:
           - standalone
           - replication
-          nullable: true
           x-walrus-ui:
             group: Basic
             order: 3
@@ -61,7 +59,6 @@ components:
           - 1
           - 3
           - 5
-          nullable: true
           x-walrus-ui:
             group: Basic
             order: 4
@@ -72,7 +69,6 @@ components:
           description: |
             Specify the deployment engine version.
           default: "8.0"
-          nullable: true
           x-walrus-ui:
             group: Basic
             order: 3
@@ -83,7 +79,6 @@ components:
             characters long and start with any lower letter, combined with number,
             or symbols: - _. \nThe database name cannot be MySQL forbidden keyword.\n"
           default: mydb
-          nullable: true
           x-walrus-ui:
             group: Basic
             order: 4
@@ -95,7 +90,6 @@ components:
             The username cannot be MySQL forbidden keyword and root.
             See https://www.alibabacloud.com/help/en/rds/developer-reference/api-rds-2014-08-15-createaccount.
           default: rdsuser
-          nullable: true
           x-walrus-ui:
             group: Basic
             order: 5
@@ -106,7 +100,6 @@ components:
             Specify the account password. The password must be 8-32 characters long and start with any letter, number, or symbols: ! # $ % ^ & * ( ) _ + - =.
             If not specified, it will use the first 16 characters of the username md5 hash value.
           format: password
-          nullable: true
           writeOnly: true
           x-walrus-ui:
             group: Basic
@@ -119,13 +112,11 @@ components:
           default:
             cpu: 0.25
             memory: 1024
-          nullable: true
           properties:
             cpu:
               default: 0.25
               description: |
                 Specify the CPU core number. Unit is core.
-              nullable: true
               title: Cpu
               type: number
               x-walrus-ui:
@@ -134,7 +125,6 @@ components:
               default: 1024
               description: |
                 Specify the memory size. Unit is megabyte.
-              nullable: true
               title: Memory
               type: number
               x-walrus-ui:
@@ -150,12 +140,10 @@ components:
             creating. Seeding increases the startup time waiting and also needs proper
             permission, like root account.
           default: {}
-          nullable: true
           properties:
             text:
               description: |
                 Configure database seeding from text.
-              nullable: true
               properties:
                 content:
                   description: |
@@ -181,15 +169,13 @@ components:
               - none
               - url
               - text
-              nullable: true
               title: Type
               type: string
               x-walrus-ui:
                 order: 1
             url:
               description: |
                 Configure database seeding from url.
-              nullable: true
               properties:
                 location:
                   description: |
@@ -201,12 +187,10 @@ components:
                 storage:
                   description: |
                     Specify a storage to store the downloaded SQL statements.
-                  nullable: true
                   properties:
                     class:
                       description: |
                         Specify the storage class. If not specified, it will use the default provisioner.
-                      nullable: true
                       title: Class
                       type: string
                       x-walrus-ui:
@@ -216,7 +200,6 @@ components:
                       description: |
                         Specify the storage size. Unit is megabyte.
                       minimum: 1024
-                      nullable: true
                       title: Size(MiB)
                       type: number
                       x-walrus-ui: