text: Title: Segfault when iterating on a transform-mapped Vector in a thread
  Body: <!-- In the following, please describe your issue in detail! -->
  <!-- If some sections do not apply, just remove them. -->
  
  ### Short description
  Take a Vector, map it with a transform, put it in a _threading_ Thread, iterate, and BOOM.
  
  ### Code to reproduce
  <!-- Please provide a minimal working example that reproduces the issue in the code block below.
       Ideally, this should be a full example someone else could run without additional setup. -->
  
  ```python
  import pyqtgraph as pg
  import threading
  
  
  def do_it():
      xform = pg.SRTTransform3D()
      v = xform.map(pg.Vector((0, 0, 0)))
      tuple(v)
  
  
  pg.mkQApp()
  threading.Thread(target=do_it).start()
  ```
  
  ### Expected behavior
  <!-- What should happen? -->
  
  ### Real behavior
  <!-- What happens? -->
  `SIGSEGV`
  
  ### Tested environment(s)
  
   * PyQtGraph version: 0.13.8dev0
   * Qt Python binding: PyQt5 5.15.10 Qt 5.15.2
   * Python version: 3.11
   * NumPy version: 1.26.3
   * Operating system: linux
   * Installation method: git
  
  ### Additional context
  
  Workaround: use a `QThread`, and this isn't an issue.