JDK8 - package sun.security.provider.certpath.ldap does not exist - Implementation suggestions

Question

I tried to compile a Spring Boot project (Java 8 + Kotlin 1.5) using Gradle 6.8 and found the error below in Java class.

error: package sun.security.provider.certpath.ldap does not exist
import sun.security.provider.certpath.ldap.LDAPCertStoreHelper;
                                          ^

I found a solution to Maven project from: https://stackoverflow.com/a/43894257/13790777 by adding this config in pom.xml which is work.

<configuration>
     <fork>true</fork>
     <compilerArgument>-XDignore.symbol.file</compilerArgument>
</configuration>

But I when can't config something like this in build.gradle.kts (Gradle Project). So, I want to know the ways to solve this problem.

If you want to reproduce this problem, you can clone this project: https://github.com/ETDA/PDFSigningAndTimestamp and try to compile this project, and you will encounter the problem immediately.