…truction warnings (deepmodeling#4907)

This PR fixes deprecation warnings that occur when `torch.tensor()` or
`paddle.to_tensor()` is called on existing tensor objects:

**PyTorch warning:**
```
UserWarning: To copy construct from a tensor, it is recommended to use sourceTensor.clone().detach() or sourceTensor.clone().detach().requires_grad_(True), rather than torch.tensor(sourceTensor).
```

**PaddlePaddle warning:**
```
UserWarning: To copy construct from a tensor, it is recommended to use sourceTensor.clone().detach(), rather than paddle.to_tensor(sourceTensor).
```

## Root Cause

The warnings were being triggered in multiple locations:

1. **PyTorch**: Test cases were passing tensor objects directly to ASE
calculators, which internally convert them using `torch.tensor()`
2. **PaddlePaddle**: Similar issues in `eval_model` function and
`to_paddle_tensor` utility, plus a TypeError where `tensor.to()` method
was incorrectly using `place=` instead of `device=`

## Solution

**For PyTorch:**
- Modified test cases to convert tensor inputs to numpy arrays before
passing to ASE calculators
- Removed redundant tensor handling in `to_torch_tensor` utility
function since the non-numpy check already handles tensors by returning
them as-is

**For PaddlePaddle:**
- Added proper type checking in `eval_model` function to handle existing
tensors with `clone().detach()`
- Removed redundant tensor handling in `to_paddle_tensor` utility
function, applying the same optimization as PyTorch
- Fixed TypeError by changing `place=` to `device=` in all `tensor.to()`
method calls (PaddlePaddle's tensor `.to()` method expects `device=`
parameter, while `paddle.to_tensor()` correctly uses `place=`)

## Changes Made

1. **`source/tests/pt/test_calculator.py`**: Fixed `TestCalculator` and
`TestCalculatorWithFparamAparam` to convert PyTorch tensors to numpy
arrays before passing to ASE calculator
2. **`deepmd/pt/utils/utils.py`**: Removed redundant tensor-specific
handling in `to_torch_tensor` function
3. **`source/tests/pd/common.py`**: Updated `eval_model` function with
type checking for PaddlePaddle tensors and fixed `tensor.to()` method
calls to use `device=` instead of `place=`
4. **`deepmd/pd/utils/utils.py`**: Removed redundant tensor-specific
handling in `to_paddle_tensor` function for consistency with PyTorch

Both utility functions now use a simplified approach where the `if not
isinstance(xx, np.ndarray): return xx` check handles all non-numpy
inputs (including tensors) by returning them unchanged, eliminating the
need for separate tensor-specific code paths.

This change is backward compatible and maintains the same functionality
while eliminating both deprecation warnings and TypeErrors, improving
code consistency between PyTorch and PaddlePaddle backends.

Fixes deepmodeling#3790.

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