Bump Spring Boot Version to Fix Outdated Dependencies

[amalpotra]

• I have searched the issues of this repository and believe that this is not a duplicate.

Description

Upgrade the Spring Boot version to address vulnerable transitive dependencies, including but not limited to:

• Tomcat
• Spring Security

The issue was identified in the published tunnel-server-fatjar, where critical marked vulnerable transitive dependencies are being pulled in.

Dependencies

• org.springframework.security:spring-security-web CVE-2024-38821
• org.springframework.security:spring-security-crypto CVE-2025-22228
• org.apache.tomcat.embed:tomcat-embed-core CVE-2024-56337, CVE-2024-52316, CVE-2024-50379