[5336870] AutoCast: Unblock LSTM from conversion (#544)

Blocking was added as a WAR for TensorRT bug 5336870, fixed in TensorRT
10.14

## What does this PR do?

**Type of change:** Bug fix <!-- Use one of the following: Bug fix, new
feature, new example, new tests, documentation. -->

**Overview:** Unblock LSTM from conversion to 16-bit in AutoCast.
Blocking was added as a WAR for TensorRT bug 5336870 (TRT only supported
FP32 LSTM). Bug was fixed in TensorRT 10.14 which is now released.


## Usage
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```python
# Add a code snippet demonstrating how to use this
```

## Testing
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## Before your PR is "*Ready for review*"
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- **Make sure you read and follow [Contributor
guidelines](https://github.com/NVIDIA/TensorRT-Model-Optimizer/blob/main/CONTRIBUTING.md)**
and your commits are signed.
- **Is this change backward compatible?**: Yes <!--- If No, explain why.
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- **Did you write any new necessary tests?**: No
- **Did you add or update any necessary documentation?**: No
- **Did you update
[Changelog](https://github.com/NVIDIA/TensorRT-Model-Optimizer/blob/main/CHANGELOG.rst)?**:
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## Additional Information
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Signed-off-by: Gal Hubara Agam <96368689+galagam@users.noreply.github.com>

Author: galagam

modelopt/onnx/autocast/precisionconverter.py

@@ -68,7 +68,7 @@ class InitializerConsumerTracker:
 OP_TYPES_NOT_SUPPORTED_IN_LOW_PRECISION = ["Upsample", "NonMaxSuppression", "Celu"]
 
 # Temporarily block these ops in low precision, as they are not supported yet
-OP_TYPES_NOT_SUPPORTED_IN_LOW_PRECISION.extend(["Scan", "If", "Loop", "LSTM"])
+OP_TYPES_NOT_SUPPORTED_IN_LOW_PRECISION.extend(["Scan", "If", "Loop"])
 
 # Mapping of op types to indices of inputs that should not be converted to low precision.
 SKIP_LOW_PRECISION_MAPPING_FP16 = {"Resize": {2}}