System information (version)

• OpenCV => 4.6.0
• Operating System / Platform => Ubuntu 20.04
• Compiler => gcc10

Detailed description

Using Opencv 4.6.0 and the new yolov7 .weights and config (.cfg) from https://github.com/WongKinYiu/yolov7/tree/darknet causes the error -> cv2/opencv-4.6.0/modules/dnn/src/darknet/darknet_io.cpp:250: error: (-212:Parsing error) Unsupported activation: silu in function 'setActivation'

weights -> https://github.com/WongKinYiu/yolov7/releases/download/v0.1/yolov7x.weights
config -> https://github.com/WongKinYiu/yolov7/blob/darknet/cfg/yolov7x_darknet.cfg
alternate config -> https://github.com/WongKinYiu/yolov7/blob/darknet/cfg/yolov7x.cfg

Steps to reproduce

# python3.9 code
import cv2
## ommited irrelevant code, the readNet method is where the issue occurs.
model_input_file = "path/to/yolov7x.weights"
model_config_file = "path/to/yolov7x_darknet.cfg" or "path/to/yolov7x.cfg"
try:
    net = cv2.dnn.readNet(model_input_file, model_config_file)
except Exception as e:
    print(f"exception when loading in weights and config -> {e}")
#### code continues

Issue submission checklist

• I report the issue, it's not a question
• I checked the problem with documentation, FAQ, open issues,
  forum.opencv.org, Stack Overflow, etc and have not found any solution
• I updated to the latest OpenCV version and the issue is still there
• There is reproducer code and related data files: videos, images, onnx, etc