Windows CI cannot find R shared library on x86

[ViralBShah]

I am seeing these errors in the Windows CI in recent PRs (Example: https://github.com/JuliaInterop/RCall.jl/actions/runs/3277665393/jobs/5395214932#step:7:222)

    Building RCall → `D:\a\RCall.jl\RCall.jl\deps\build.log`
ERROR: LoadError: Could not find library C:\R\bin\i386\R.dll. Make sure that R shared library exists.
Stacktrace:
 [1] error(s::String)
   @ Base .\error.jl:35
 [2] validate_libR(libR::String)
   @ Main D:\a\RCall.jl\RCall.jl\deps\setup.jl:11
 [3] locate_libR(Rhome::SubString{String})
   @ Main D:\a\RCall.jl\RCall.jl\deps\setup.jl:43
 [4] top-level scope
   @ D:\a\RCall.jl\RCall.jl\deps\build.jl:58
 [5] include(fname::String)
   @ Base.MainInclude .\client.jl:476
 [6] top-level scope
   @ none:5
in expression starting at D:\a\RCall.jl\RCall.jl\deps\build.jl:11
ERROR: Error building `RCall`: 

[ViralBShah]

@DilumAluthge Might you know what is going on here? We use the R setup provided on github actions by r-lib.

[DilumAluthge]

I'm assuming that in CI, we should let RCall install R via Conda, instead of trying to find it on the system.

[ViralBShah]

I thought that the github actions thing would set R up the right way. So perhaps either install the r-lib provided action or conda - but not both?

[ViralBShah]

Some discussion about the right path: #459 (comment)