fix: Update Spring Boot to 3.5.0 for @ClientRegistrationId support

- Upgrade Spring Boot from 3.1.3 to 3.5.0
- Add spring-boot-starter-oauth2-client dependency

@ClientRegistrationId requires Spring Security 6.5+ (Spring Boot 3.5+)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: ng-galien

samples/client/petstore/spring-http-interface-oauth/pom.xml

@@ -12,7 +12,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>3.1.3</version>
+        <version>3.5.0</version>
         <relativePath/> <!-- lookup parent from repository -->
     </parent>
 
@@ -67,6 +67,10 @@
             <artifactId>jackson-databind-nullable</artifactId>
             <version>0.2.8</version>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-oauth2-client</artifactId>
+        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>