[R] Allow overriding the libarrow static lib version

[paleolimbot]

Describe the enhancement requested

We've had a few discussions about using nightly libarrow binaries to help with development. Ideally there would be a way to look up the URL of the latest nightly version (or maybe there is one already)...in the meantime (and for the purposes of testing what will happen when we submit to CRAN), there should be a mechanism to override the version used to determine the binary URL.

Component(s)

R

[paleolimbot]

Linking some older issues where this has been discussed:

• [R] Improve configure script for contributor experience #35049
• [R] Developer setup guides need more context on SSL versions #35884 (comment)
• [R] [Packaging] Developing + {LIBARROW_BINARY=true} #27839