GH-49037: [Benchmarking] Install R from non-conda source for benchmarking

[thisisnic]

Rationale for this change

Slow benchmarks due to conda duckdb building from source

What changes are included in this PR?

Try ditching conda and installing R via rig and using PPM binaries

Are these changes tested?

I'll try running

Are there any user-facing changes?

Nope

• GitHub Issue: [Benchmarking] Install R from non-conda source for benchmarking #49037

[thisisnic]

@ursabot please benchmark

[rok]

Benchmark runs are scheduled for commit 70dd4d3. Watch https://buildkite.com/apache-arrow and https://conbench.arrow-dev.org for updates. A comment will be posted here when the runs are complete.

[conbench-apache-arrow]

Thanks for your patience. Conbench analyzed the 3 benchmarking runs that have been run so far on PR commit 70dd4d3.

There were 5 benchmark results indicating a performance regression:

• Pull Request Run on arm64-t4g-2xlarge-linux at 2026-01-27 23:36:11Z
  • MoveEmptyVector (C++) with params=<STATIC_VECTOR(int)>, source=cpp-micro, suite=arrow-small-vector-benchmark
  • MoveShortVector (C++) with params=<STD_VECTOR(int)>, source=cpp-micro, suite=arrow-small-vector-benchmark
• and 3 more (see the report linked below)

The full Conbench report has more details.

[thisisnic]

This PR adds an install_r() function that installs R via https://github.com/r-lib/rig instead of using conda R. The goal is to speed up R benchmarks by allowing RSPM binary packages (like duckdb) to be used instead of compiling from source.

However, this PR alone isn't sufficient - the benchmark CI infrastructure lives in a separate repo (https://github.com/arctosalliance/arrow-benchmarks-ci) which currently includes r in its conda environment creation. Even though this PR adds install_r(), conda R gets installed first, so the command -v R check passes and rig is never used.

Companion PR needed: arctosalliance/arrow-benchmarks-ci#1 - removes r from conda env and calls the install_r hook from this PR.

The arctosalliance PR depends on this one being merged first.

[thisisnic]

@rok This has got a bit messy as there may be code duplicated between the arctos repo and the Arrow repo, but I think this makes sense? Or do you reckon I should I move all of this to the other repo so we don't have dependent PRs?

[rok]

This looks sensible @thisisnic, please merge and verify and ping me if there's another cycle needed.