Fix gradle task dependencies

[wadoon]

Nightly deployer got destroyed by ANTLR refactoring:

A problem was found with the configuration of task ':key.ncore:sourcesJar' (type 'Jar').
  - Gradle detected a problem with the following location: '/home/runner/work/key/key/key.ncore/build/generated-src/antlr/main'.
    
    Reason: Task ':key.ncore:sourcesJar' uses this output of task ':key.ncore:runAntlr4Key' without declaring an explicit or implicit dependency. This can lead to incorrect results being produced, depending on what order the tasks are executed.
    
    Possible solutions:
      1. Declare task ':key.ncore:runAntlr4Key' as an input of ':key.ncore:sourcesJar'.
      2. Declare an explicit dependency on ':key.ncore:runAntlr4Key' from ':key.ncore:sourcesJar' using Task#dependsOn.
      3. Declare an explicit dependency on ':key.ncore:runAntlr4Key' from ':key.ncore:sourcesJar' using Task#mustRunAfter.
    
    For more information, please refer to https://docs.gradle.org/9.5.1/userguide/validation_problems.html#implicit_dependency in the Gradle documentation.

Waiting for https://github.com/KeYProject/key/actions/runs/27870275890 to be green.

[Drodt]

Thanks!