### Describe the issue:
Per the [discussion here](https://discourse.pymc.io/t/m…odeling-a-spectrum-of-gaussians-with-smc/14854/2), SMC does not properly handle custom `initval` for free RVs. This is apparent when sampling from distributions with the `Ordered()` transformation, where it is imperative that the `initval` be ordered else the model will fail to sample due to a `NaN` logp at the initial point.
### Reproduceable code example:
```python
import pymc as pm
from pymc.distributions.transforms import Ordered
with pm.Model() as model:
a = pm.Normal("a", mu=0.0, sigma=1.0, size=(3,), transform=Ordered(), initval=[-1.0, 0.0, 1.0])
b = pm.Normal("b", mu=a, sigma=1.0, observed=[0.0, 0.0, 0.0])
with model:
trace = pm.sample_smc()
```
### Error message:
```shell
<details>
---------------------------------------------------------------------------
_RemoteTraceback Traceback (most recent call last)
_RemoteTraceback:
"""
Traceback (most recent call last):
File "/home/twenger/miniconda3/envs/pymc/lib/python3.11/concurrent/futures/process.py", line 256, in _process_worker
r = call_item.fn(*call_item.args, **call_item.kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/twenger/miniconda3/envs/pymc/lib/python3.11/site-packages/pymc/smc/sampling.py", line 346, in _sample_smc_int
smc.update_beta_and_weights()
File "/home/twenger/miniconda3/envs/pymc/lib/python3.11/site-packages/pymc/smc/kernels.py", line 273, in update_beta_and_weights
ESS = int(np.exp(-logsumexp(log_weights * 2)))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
ValueError: cannot convert float NaN to integer
"""
The above exception was the direct cause of the following exception:
ValueError Traceback (most recent call last)
Cell In[1], line 9
6 b = pm.Normal("b", mu=a, sigma=1.0, observed=[0.0, 0.0, 0.0])
8 with model:
----> 9 trace = pm.sample_smc()
File ~/miniconda3/envs/pymc/lib/python3.11/site-packages/pymc/smc/sampling.py:217, in sample_smc(draws, kernel, start, model, random_seed, chains, cores, compute_convergence_checks, return_inferencedata, idata_kwargs, progressbar, **kernel_kwargs)
208 params = (
209 draws,
210 kernel,
211 start,
212 model,
213 )
215 t1 = time.time()
--> 217 results = run_chains(chains, progressbar, params, random_seed, kernel_kwargs, cores)
219 (
220 traces,
221 sample_stats,
222 sample_settings,
223 ) = zip(*results)
225 trace = MultiTrace(traces)
File ~/miniconda3/envs/pymc/lib/python3.11/site-packages/pymc/smc/sampling.py:422, in run_chains(chains, progressbar, params, random_seed, kernel_kwargs, cores)
415 # update the progress bar for this task:
416 progress.update(
417 status=f"Stage: {stage} Beta: {beta:.3f}",
418 task_id=task_id,
419 refresh=True,
420 )
--> 422 return tuple(cloudpickle.loads(r.result()) for r in done)
File ~/miniconda3/envs/pymc/lib/python3.11/site-packages/pymc/smc/sampling.py:422, in <genexpr>(.0)
415 # update the progress bar for this task:
416 progress.update(
417 status=f"Stage: {stage} Beta: {beta:.3f}",
418 task_id=task_id,
419 refresh=True,
420 )
--> 422 return tuple(cloudpickle.loads(r.result()) for r in done)
File ~/miniconda3/envs/pymc/lib/python3.11/concurrent/futures/_base.py:449, in Future.result(self, timeout)
447 raise CancelledError()
448 elif self._state == FINISHED:
--> 449 return self.__get_result()
451 self._condition.wait(timeout)
453 if self._state in [CANCELLED, CANCELLED_AND_NOTIFIED]:
File ~/miniconda3/envs/pymc/lib/python3.11/concurrent/futures/_base.py:401, in Future.__get_result(self)
399 if self._exception:
400 try:
--> 401 raise self._exception
402 finally:
403 # Break a reference cycle with the exception in self._exception
404 self = None
ValueError: cannot convert float NaN to integer
</details>
```
### PyMC version information:
<details>
pymc 5.16.2 (conda)
</details>
### Context for the issue:
_No response_
