opencv_ffmpeg.dll not generated with vcpkg install opencv[ffmpeg]

[G4419]

Describe the bug
When installing OpenCV via vcpkg with the ffmpeg feature enabled, the opencv_ffmpeg*.dll file is not generated. This results in issues with opening video files such as .mp4.

Environment

• OS: Windows11
• Compiler: Microsoft Visual C++ 2022

To Reproduce
./vcpkg install opencv[ffmpeg] --triplet=x64-windows
Check the output directory for the opencv_ffmpeg*.dll file (e.g., /installed/x64-windows/bin).

Expected behavior
The opencv_ffmpeg*.dll file should be present in the bin directory after successfully installing OpenCV with the ffmpeg feature.

Failure logs
No errors during installation, but the opencv_ffmpeg*.dll file is missing.
The application fails to open .mp4 files.