Do not require internet connection for `example_package`

[peterdesmet]

example_package currently has a remote $directory:

> library(frictionless)
> example_package$directory
[1] "https://raw.githubusercontent.com/frictionlessdata/frictionless-r/main/inst/extdata"

That means an internet connection is need to read resources. This was by design for some tests, but should probably be altered so more tests can run without an internet connection.

https://github.com/frictionlessdata/frictionless-r/blob/b6d330858f9c3ce1bc95e1c23520766f0ffea3d5/R/data.R#L16-L21

Need to investigate first what tests would fail (on GitHub CI) if the directory is local.