Update ByteBuddy dependency for Java 25 compatibility

[ialveswr]

Problem

MockServer 5.15.0 includes a transitive ByteBuddy dependency that predates Java 25 support.
ByteBuddy versions prior to 1.17.5 do not support Java 25 (class file version 69) and can cause errors such as:

Java 25 (69) is not supported by the current version of Byte Buddy which officially supports Java 24 (68) - update Byte Buddy or set net.bytebuddy.experimental as a VM property

I discovered this while researching compatibility issues during a Java 25 upgrade.
I applied the workaround below and did not encounter the error myself without the workaround either, but wanted to raise this for tracking.

Workaround

Exclude ByteBuddy from MockServer and explicitly declare a newer version:

testImplementation('org.mock-server:mockserver-junit-jupiter:5.15.0') {
    exclude group: 'net.bytebuddy'
}
testImplementation 'net.bytebuddy:byte-buddy:1.18.3'
testImplementation 'net.bytebuddy:byte-buddy-agent:1.18.3'