Fix implicit Node to Output conversion in transformations (#32535)
### Details:
This PR fixes implicit Node to Output conversion issues found left after
https://github.com/openvinotoolkit/openvino/pull/30337
Changes:
- lora_subgraph_horizontal_fusion.cpp: Use input_value() instead of
get_input_node_shared_ptr() when filling OutputVector for
LoraSubgraphFused constructor
- propagate_precision.cpp: Use input_value() instead of
get_input_node_shared_ptr() when creating ConvertSaturation node
These issues are classified as non-critical because the inputs are
typically single-output nodes (ReadValue, Convert, etc.) and don't cause
exceptions in real scenarios. However, they violate the best practice of
avoiding implicit conversions when creating nodes.
### Tickets:
- 165972
openvino
5b63eb2b - Fix implicit Node to Output conversion in transformations (#32535)
