Remove sentinel useless annotation

[ruansheng8]

Describe what this PR does / why we need it

When my application does not used Hibernate Validator dependency , it will fail to start :

2023-01-16 16:27:54.443  WARN 4976 --- [           main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'com.alibaba.cloud.sentinel.custom.SentinelAutoConfiguration': Unsatisfied dependency expressed through field 'properties'; nested exception is org.springframework.boot.context.properties.ConfigurationPropertiesBindException: Error creating bean with name 'spring.cloud.sentinel-com.alibaba.cloud.sentinel.SentinelProperties': Could not bind properties to 'SentinelProperties' : prefix=spring.cloud.sentinel, ignoreInvalidFields=false, ignoreUnknownFields=true; nested exception is javax.validation.NoProviderFoundException: Unable to create a Configuration, because no Bean Validation provider could be found. Add a provider like Hibernate Validator (RI) to your classpath.
2023-01-16 16:27:54.448  INFO 4976 --- [           main] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2023-01-16 16:27:54.452 ERROR 4976 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   : 

***************************
APPLICATION FAILED TO START
***************************

Description:

The Bean Validation API is on the classpath but no implementation could be found

Action:

Add an implementation, such as Hibernate Validator, to the classpath

See SentinelProperties.java

@ConfigurationProperties(prefix = SentinelConstants.PROPERTY_PREFIX)
@Validated
public class SentinelProperties {

and when I remove @Validated , it works

btw , We can use hibernate-validator dependency to solve it :

        <dependency>
            <groupId>org.hibernate.validator</groupId>
            <artifactId>hibernate-validator</artifactId>
        </dependency>

but i don't see any field validation annotation in this class , so i remove it.

Describe how to verify it

Verify it using the following dependencies

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
        </dependency>
        
        
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-circuitbreaker-sentinel</artifactId>
        </dependency>
    
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
        </dependency>
            

[steverao]

LGTM, thanks @ruansheng8 BTW, please sync to other main branchs.