CI: Also build with RTPS=ON

[anselmolsm]

Depends on #16

[zehortigoza]

Oh nice.
So not even in Ubuntu there is packages for RTPS?
So I guess it need to be integrated to the build as https://github.com/PX4/OpticalFlow is.
@avinash-palleti

[anselmolsm]

Yep. I don't know how often API changes, but in order to have better control over the fast-rtps version used by optical-flow, it makes sense to add that as a module.