Make one of the tests more robust
The text-mixed-color-nocairo test was using a 20pt font, which results in 16.6 pixels, which is prone to triggering rounding errors and problems with fractional node bounds. Make it use 20px instead.
The text-mixed-color-nocairo test was using a 20pt font, which results in 16.6 pixels, which is prone to triggering rounding errors and problems with fractional node bounds. Make it use 20px instead.