fix: Support stream readers before TensorRT 10.7

[suharvest]

What does this PR do?

Makes file-backed TensorRT engine deserialization compile with TensorRT
versions before 10.7:

• TensorRT 10.7+ keeps the existing IStreamReaderV2 implementation,
  asynchronous device reads, pinned transfer buffers, and seek().
• Earlier TensorRT versions use the available IStreamReader host-read
  contract and reuse the same file descriptor, offset, EOF, and error handling.

The version boundary matches the introduction of IStreamReaderV2; TensorRT
11 and newer continue to use the V2 path.

Scope

• One runtime source file.
• No engine format, runtime API, model, or server changes.
• The current TensorRT 10.7+ path is retained.

Validation

• Checked the reader and deserialization contracts against the NVIDIA
  TensorRT 10.3 and 10.7 headers.
• clang-format, codespell, git diff --check, and merge-tree validation
  pass.
• The change is a single signed-off commit on current main.

The validation machine does not contain TensorRT/CUDA headers, so complete
builds against the real 10.3 and 10.7 SDKs and real-engine deserialization are
still requested from CI or Jetson validation.

Closes #140.