nanoowl is broken by updated dependencies giving error cv2.error in owl_drawing.py

[SeanCondon]

As described in this forum thread nanoowl gives this error:

Traceback (most recent call last):
  File "/opt/nanoowl/examples/owl_predict.py", line 88, in <module>
    image = draw_owl_output(image, output, text=text, draw_text=True)
  File "/opt/nanoowl/nanoowl/owl_drawing.py", line 51, in draw_owl_output
    cv2.rectangle(
cv2.error: OpenCV(4.11.0) :-1: error: (-5:Bad argument) in function 'rectangle'
> Overload resolution failed:
>  - img marked as output argument, but provided NumPy array marked as readonly
>  - img marked as output argument, but provided NumPy array marked as readonly
>  - Expected Ptr<cv::UMat> for argument 'img'
>  - Expected Ptr<cv::UMat> for argument 'img'

when running with the docker image dustynv/nanoowl:r36.4.0 pulled from Nvidia's own registry.

This can be easily reproduced by building the docker image locally by running jetson-containers build nanoowl where the tests fail with:

[00:21:59] Failed building:  nanoowl

Traceback (most recent call last):
  File "/home/scondon/jetson-containers/jetson_containers/build.py", line 129, in <module>
    build_container(**vars(args))
  File "/home/scondon/jetson-containers/jetson_containers/container.py", line 240, in build_container
    test_container(container_name, pkg, simulate, build_idx=idx)
  File "/home/scondon/jetson-containers/jetson_containers/container.py", line 426, in test_container
    status = subprocess.run(cmd.replace(_NEWLINE_, ' '), executable='/bin/bash', shell=True, check=True)
  File "/usr/lib/python3.10/subprocess.py", line 526, in run
    raise CalledProcessError(retcode, process.args,
subprocess.CalledProcessError: Command 'docker run -t --rm --network=host --privileged --runtime=nvidia   --volume /home/scondon/jetson
-containers/packages/vit/nanoowl:/test   --volume /home/scondon/jetson-containers/data:/data   nanoowl:r36.4.tegra-aarch64-cu126-22.04-
nanoowl     /bin/bash -c '/bin/bash /test/test.sh' 2>&1 | tee /home/scondon/jetson-containers/logs/20250729_213533/test/23-1_nanoowl_r3
6.4.tegra-aarch64-cu126-22.04-nanoowl_test.sh.txt; exit ${PIPESTATUS[0]}' returned non-zero exit status 1.

I suspect what's going on here is that some dependency is updated since this was created originally 2 years ago, and has a problem passing in readonly numpy arrays for cv2.rectangle. I will create a PR to try to fix this