Cant use lambda as python planning entity attribute

[luxaritas]

Describe the bug
When instantiating a planning entity with a lambda as an attribute, an error will be thrown at runtime

Expected behavior
It should work equivalently to passing a function defined with def

Actual behavior

Traceback (most recent call last):
  File "/home/jonathan/Development/eterna/OpenKnotScorePipeline/repro.py", line 49, in <module>
    solver_factory.build_solver().solve(problem)
  File "/home/jonathan/Development/eterna/OpenKnotScorePipeline/.venv/lib/python3.12/site-packages/timefold/solver/_solver.py", line 115, in solve
    return unwrap_python_like_object(java_solution)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/jonathan/Development/eterna/OpenKnotScorePipeline/.venv/lib/python3.12/site-packages/_jpyinterpreter/conversions.py", line 682, in unwrap_python_like_object
    update_python_object_from_java(python_like_object, clone_map)
  File "/home/jonathan/Development/eterna/OpenKnotScorePipeline/.venv/lib/python3.12/site-packages/_jpyinterpreter/conversions.py", line 740, in update_python_object_from_java
    getattr(java_object, '$writeFieldsToCPythonReference')(JProxy(OpaquePythonReference,
  File "/home/jonathan/Development/eterna/OpenKnotScorePipeline/.venv/lib/python3.12/site-packages/_jpyinterpreter/jvm_setup.py", line 188, in accept
    unwrapped_object = unwrap_python_like_object(value,
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/jonathan/Development/eterna/OpenKnotScorePipeline/.venv/lib/python3.12/site-packages/_jpyinterpreter/conversions.py", line 593, in unwrap_python_like_object
    out.append(unwrap_python_like_object(item, clone_map, default))
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/jonathan/Development/eterna/OpenKnotScorePipeline/.venv/lib/python3.12/site-packages/_jpyinterpreter/conversions.py", line 682, in unwrap_python_like_object
    update_python_object_from_java(python_like_object, clone_map)
  File "/home/jonathan/Development/eterna/OpenKnotScorePipeline/.venv/lib/python3.12/site-packages/_jpyinterpreter/conversions.py", line 740, in update_python_object_from_java
    getattr(java_object, '$writeFieldsToCPythonReference')(JProxy(OpaquePythonReference,
  File "/home/jonathan/Development/eterna/OpenKnotScorePipeline/.venv/lib/python3.12/site-packages/_jpyinterpreter/jvm_setup.py", line 188, in accept
    unwrapped_object = unwrap_python_like_object(value,
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/jonathan/Development/eterna/OpenKnotScorePipeline/.venv/lib/python3.12/site-packages/_jpyinterpreter/conversions.py", line 726, in unwrap_python_like_object
    return getattr(importlib.import_module(module_name), function_name)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: module '__main__' has no attribute '$_60_$lambda$_62_$'

To Reproduce

from typing import Annotated, Callable
from dataclasses import dataclass, field
from timefold.solver.domain import (
    PlanningVariable,
    PlanningEntityCollectionProperty,
    PlanningScore, ValueRangeProvider,
    planning_entity, planning_solution
)
from timefold.solver.score import HardSoftScore, constraint_provider
from timefold.solver import SolverFactory
from timefold.solver.config import SolverConfig, ScoreDirectorFactoryConfig, TerminationConfig, Duration

@planning_entity
@dataclass
class ResourceConfiguration:
    f: Callable[[int], int]

    cpus: Annotated[int, PlanningVariable(value_range_provider_refs = ['cpu_range'])] = 1

    def get_cpu_range(self) -> Annotated[list[int], ValueRangeProvider(id='cpu_range')]:
        return list(range(1, 5))

@planning_solution
@dataclass
class Schedule:
    resource_configurations: Annotated[list[ResourceConfiguration], PlanningEntityCollectionProperty]

    score: Annotated[HardSoftScore, PlanningScore] = field(default=None)

@constraint_provider
def constraints(factory):
    return [
        factory.for_each(ResourceConfiguration).penalize(HardSoftScore.ONE_HARD).as_constraint('static')
    ]

solver_factory = SolverFactory.create(
    SolverConfig(
        solution_class=Schedule,
        entity_class_list=[ResourceConfiguration],
        score_director_factory_config=ScoreDirectorFactoryConfig(
            constraint_provider_function=constraints
        ),
        termination_config=TerminationConfig(
            spent_limit=Duration(seconds=1)
        )
    )
)
problem = Schedule([ResourceConfiguration(lambda x: x*2, 1)])
solver_factory.build_solver().solve(problem)

Environment

Timefold Solver Version or Git ref:
1.17.0

Output of java -version:

openjdk version "23" 2024-09-17
OpenJDK Runtime Environment (build 23)
OpenJDK 64-Bit Server VM (build 23, mixed mode, sharing)

Output of uname -a or ver:

Linux 6.6.63-1-MANJARO #1 SMP PREEMPT_DYNAMIC Sat Nov 23 02:15:34 UTC 2024 x86_64 GNU/Linux

[triceo]

As of today, Timefold halted any further development of the Python solver.
Find out more here: #1698

Closing this issue.