Bump gstly and verify hw-accelerated video decoding

[apockill]

The new version of gstly supports hardware accelerated video decoding. Let's bump gstly and test adding the following environment variables to our snap/pyinstaller builds:

      # Prefer NVCODEC hardware decoding over all other options
      GSTLY_NVCODEC_RANK: 258
      # Prefer VA-API hardware decoding over software decoding
      GSTLY_VAAPI_RANK: 257

Let's also see what happens on the windows build. Does msys's gstreamer include nvcodec?

[velovix]

The Snap currently isn't expected to work with VA-API or NVCODEC unfortunately, but I wouldn't let that block this task. We just need to make sure bumping Gstly doesn't break anything for the Snap.

[apockill]

The pyinstaller bash script for linux should def have the environment variable added though.

Or maybe instead of putting it in the bash script, the client could set these variables itself? I'm not sure the best way to handle that.

In Windows, the executable is launched directly.

[velovix]

Or maybe instead of putting it in the bash script, the client could set these variables itself?

Potentially. I'm not sure if Python will be able to set these environment variables in such a way that GStreamer will see them. If not, we can always provide a way in Gstly to set these values programmatically as well.

In Windows, the executable is launched directly.

True, although in the short term this may not matter because we don't support hardware acceleration on Windows yet.