ARROW-18061: [CI][R] Reduce number of jobs on every commit

[nealrichardson]

• Force tests: true fully contains all tests in the false version, so false is redundant
• The CentOS 7 job previously was useful to catch gcc 4.8 issues, but that's no longer a problem, and the CentOS with devtoolset-8 variant is already tested nightly
• The Windows builds can be pruned if we test only on current release and development version, which only use UCRT. We test the older build nightly in the r-binary-packages workflow

[pitrou]

@assignUser What do you think?

[assignUser]

Yes I agree, this makes sense. The nightly builds are quite thorough and we can always run crossbow jobs to be sure for larger changes.

With this change we can also remove the additional "Download artifact" steps and renaming of the libarrow binary from the windows jobs. (we could also inline the force test matrix but 🤷)

[ursabot]

Benchmark runs are scheduled for baseline = ee1f763 and contender = 2f57194. 2f57194 is a master commit associated with this PR. Results will be available as each benchmark for each run completes.
Conbench compare runs links:
[Finished ⬇️0.0% ⬆️0.0%] ec2-t3-xlarge-us-east-2
[Failed ⬇️0.0% ⬆️13.89%] test-mac-arm
[Finished ⬇️0.54% ⬆️5.98%] ursa-i9-9960x
[Finished ⬇️0.04% ⬆️0.0%] ursa-thinkcentre-m75q
Buildkite builds:
[Finished] 2f57194f ec2-t3-xlarge-us-east-2
[Failed] 2f57194f test-mac-arm
[Finished] 2f57194f ursa-i9-9960x
[Finished] 2f57194f ursa-thinkcentre-m75q
[Finished] ee1f7630 ec2-t3-xlarge-us-east-2
[Failed] ee1f7630 test-mac-arm
[Finished] ee1f7630 ursa-i9-9960x
[Finished] ee1f7630 ursa-thinkcentre-m75q
Supported benchmarks:
ec2-t3-xlarge-us-east-2: Supported benchmark langs: Python, R. Runs only benchmarks with cloud = True
test-mac-arm: Supported benchmark langs: C++, Python, R
ursa-i9-9960x: Supported benchmark langs: Python, R, JavaScript
ursa-thinkcentre-m75q: Supported benchmark langs: C++, Java

[ursabot]

['Python', 'R'] benchmarks have high level of regressions.
test-mac-arm
ursa-i9-9960x