chore(deps): Update Spring boot dependency for Gradle sample aws well

Author: deki

samples/springboot2/pet-store/build.gradle

@@ -8,7 +8,7 @@ repositories {
 
 dependencies {
   implementation (
-          implementation('org.springframework.boot:spring-boot-starter-web:2.6.7') {
+          implementation('org.springframework.boot:spring-boot-starter-web:2.7.3') {
             exclude group: 'org.springframework.boot', module: 'spring-boot-starter-tomcat'
           },
           'com.amazonaws.serverless:aws-serverless-java-container-springboot2:[1.4,)',