[BUG] Sony ARW medium and small compression 15 bit per sample files are unsupported

**Describe the bug**

Importing a Sony ARW Medium or Small compression file with 15 bits per sample is unsupported in OIIO.

Other Sony ARW Medium or Small compression files which are not 15 bits per sample open correctly and are supported.

**OpenImageIO version and dependencies**

```
oiiotool --buildinfo
OIIO 2.5.12.0 | MacOS/ARM
Build compiler: Apple clang 15.0 | C++14/201402
HW features enabled at build: neon
Dependencies: Boost 1.85.0, BZip2 1.0.8, FFmpeg 6.0, fmt 10.2.1, Freetype
2.13.2, GIF 5.2.2, Libheif 1.17.6, libjpeg-turbo 3.0.3, LibRaw 0.21.2,
OpenColorIO 2.3.2, OpenEXR 3.2.4, OpenVDB NONE, PNG 1.6.43, pugixml 1.14,
pybind11 2.12.0, Python 3.12.3, Robinmap, TBB 2021.12.0, TIFF 4.6.0, WebP
1.4.0, ZLIB 1.2.12
```

**To Reproduce**

Steps to reproduce the behavior:
1. Download the ARW file
2. Try to convert to a different format with OIIO
3. This error appears.
4. I expected it to output.

```
oiiotool /Users/topazlabs/Downloads/A1A04973.ARW -o ~/Downloads/arw.png
oiiotool ERROR: read : Could not open file "/Users/topazlabs/Downloads/A1A04973.ARW", Unsupported file format or not RAW file
Full command line was:
> oiiotool /Users/topazlabs/Downloads/A1A04973.ARW -o /Users/topazlabs/Downloads/arw.png
```

**Evidence**

https://www.dropbox.com/scl/fi/y19jqq4q3rh1wv7810048/A1A04973.ARW?rlkey=pnrdm0oo0hlpbkep1goczk1da&st=ij4br4bn&dl=0