title: PyQtGraph disable mouse wheel, but leave other functions of the mouse untouched
body: <p>I have a pyqtgraph.ViewBox widget with an image in it. The mouse is enabled, so I can select a rectangle on the image and it will be zoomed. But there is an unwanted feature, the zooming occurs on the mouse wheel scrolling aswell.</p>
  <p>How can I disable the mouse wheel only, and leave the rest as is?</p>
  <pre><code>from PyQt5.QtWidgets import QApplication, QMainWindow
  import pyqtgraph as pg
  import cv2
  
  
  class MainWindow(QMainWindow):
      def __init__(self):
          super().__init__()
          pg.setConfigOption('imageAxisOrder', 'row-major')
          pg.setConfigOption('leftButtonPan', False)  # if False, then dragging the left mouse button draws a rectangle
      
          self.grid = pg.GraphicsLayoutWidget()
          self.top_left = self.grid.addViewBox(row=1, col=1)
  
          image = cv2.imread('/path/to/your/image.jpg', cv2.IMREAD_UNCHANGED)
          self.image_item = pg.ImageItem()
          self.image_item.setImage(image)
          self.top_left.addItem(self.image_item)
  
          self.setCentralWidget(self.grid)
  
  
  def main():
      app = QApplication([])
      window = MainWindow()
      window.show()
      app.exec_()
  
  
  if __name__ == '__main__':
      main()
  </code></pre>