Prevent Inkscape from making a style attribute while using the Fill tool

Question

I am using dashboarding software where I can embed svg images and fill them in automatically. For this a fill has to be assigned, and the dashboard studio changes that fill value dynamically.

Howeve, this only works when the svg is like this:

<rect id="rect3" 
  fill="#123456"
  width="9"
  height="9"
  x="20"
  y="10"
 />

However, when I use the "Fill and Stroke" tool in Inkscape, it applies the fill within a style attribute:

 <rect id="rect3" 
  style="fill:#123456"
  width="9"
  height="9"
  x="20"
  y="10"
 />

Even when I go into the code to fix this, it only works until you use the fill tool again, as it will add the style attribute, which overrides the fill attribute and which unfortunately makes my dashboarding software not fill in the color dynamically:

 <rect id="rect3" 
  fill="#123456"
  style="fill:#00ff00"
  width="9"
  height="9"
  x="20"
  y="10"
 />

Is there a way to make Inkscape (always) use the Fill attribute instead of the Style attribute?