[WIP] Multi gpu tests and predict_tile error #646

[bw4sz]

This is still a work in progress, closes #646 and #467.

• create a test that reproduces and can bypass if not multi-gpu
• identify source of error.

[bw4sz]

Profile results of moving cpu() call to the end of the prediction epoch.

# Profile predict_tile
from deepforest import main
import time

# Profile predict_tile
path = "/orange/ewhite/NeonData/OSBS/DP3.30010.001/neon-aop-products/2023/FullSite/D03/2023_OSBS_7/L3/Camera/Mosaic/2023_OSBS_7_406000_3291000_image.tif"
m = main.deepforest()
m.use_release()

start_time = time.time()
m.predict_tile(path)
end_time = time.time()

execution_time = end_time - start_time
print(f"Execution time: {execution_time} seconds")

On HPC with 2 available GPUs.
Original: (fails due to multi-gpu)

PR: 43.12