sn74lvc1t45 pullup on the DIR line
Here is the design process to calculate a pullup resistor value (applicable to virtually any situation). The general idea is that the II leakage current from the chip (from the DIR pin) will induce a voltage drop across the pullup, and that voltage drop should not make the input voltage go below the VIH high-level input voltage limit indicated in the datasheet.

So:

Rmax = (VCCmin - VIH) / IImax

All the inputs, except VCCmin are given in the chip datasheet. VCCmin is dictated by whatever chip you're using as a supply (typically 3.3V - 5%).

Here we go:

Rmax = (3.135V - 2V) / 2µA = 567.5 kOhm

But this is the maximum value. There is no minimum value required to have the appropriate level applied to the input. So if the DIR input is fixed, you can actually just tie it directly to the VCC supply (just like you could tie it directly to GND in the original situation you described).

Note that, in situations when you really need a pullup (e.g. I2C), besides the computation given above that gives the static limit, you typically have to choose a compromise between faster signal rise time (lower pullup values) and lower power consumption (higher pullup values).