Note also that 0.1 rad is about 5.72958°, so that might be a rather big step depending on what you want to do. If you want to use degrees, stick to degrees, and only convert the angle to radians when you need to calculate some sin or cos - @Thierry Lathuille

Updated Code:

 time.sleep(2)
    radius = 110#px
    angle  = 90
    step=0
    
    while True:
        x= radius * math.cos((math.radians(angle)))
        y = radius * math.sin((math.radians(-angle)))
        win32api.SetCursorPos((int( x+xcentre),int(y+ycentre)))
        
    
        
        if math.radians(angle) >= 2*math.pi  + math.pi/2:
            break
        mx,my = pyautogui.position()
        if (angle - 90)%cycles==0:
            print("black")
            pyautogui.mouseDown(button='left')
            position_list.append(mx)
            position_list.append(my)
            time.sleep(1)

        

        angle+=1
    pyautogui.mouseUp(button='left')