fix: pom.xml to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JAVA-ORGAPACHETOMCATEMBED-8523186
- https://snyk.io/vuln/SNYK-JAVA-ORGAPACHETOMCATEMBED-8547999
- https://snyk.io/vuln/SNYK-JAVA-CHQOSLOGBACK-8539865
- https://snyk.io/vuln/SNYK-JAVA-CHQOSLOGBACK-8539866
- https://snyk.io/vuln/SNYK-JAVA-CHQOSLOGBACK-8539867

Author: snyk-bot

pom.xml

@@ -16,7 +16,7 @@
     <description>Demo project for graphql-springboot-api-integration</description>
     <properties>
         <java.version>1.8</java.version>
-        <spring-boot.version>3.1.4</spring-boot.version>
+        <spring-boot.version>3.3.7</spring-boot.version>
         <json-smart.version>5.2.2</json-smart.version>
     </properties>