Fix test dependencies of WebMvcTestOAuth2Tests

This commit fixes the dependencies of spring-boot-test-autoconfigure so
that it does not depend on a starter.

See gh-45654

Author: snicoll

spring-boot-project/spring-boot-test-autoconfigure/build.gradle

@@ -110,9 +110,9 @@ dependencies {
 	testImplementation("org.mockito:mockito-junit-jupiter")
 	testImplementation("org.skyscreamer:jsonassert")
 	testImplementation("org.springframework:spring-core-test")
-	testImplementation("org.springframework.boot:spring-boot-starter-oauth2-client")
 	testImplementation("org.springframework.hateoas:spring-hateoas")
 	testImplementation("org.springframework.plugin:spring-plugin-core")
+	testImplementation("org.springframework.security:spring-security-oauth2-client")
 	testImplementation("org.thymeleaf:thymeleaf")
 }