GH-49737: [R][CI] Disable Rhub GCC 12 and GCC 13 with LTO jobs - images no longer match CRAN

[thisisnic]

Rationale for this change

Disable failing + out of date CI jobs until we have a container with GCC 15 to replace them

What changes are included in this PR?

Disable them - leave commented out as we'll replace later

Are these changes tested?

No

Are there any user-facing changes?

No

• GitHub Issue: [R][CI] Disable Rhub GCC 12 and GCC 13 with LTO jobs — images no longer match CRAN #49737

[raulcd]

Rhub GCC 13 with LTO has been failing on CI for several weeks but Rhub GCC 12 seems to be successful. Example for last nightly:
https://github.com/apache/arrow/actions/runs/24381689114/job/71206402529

Should we still remove that one too?

[thisisnic]

Rhub GCC 13 with LTO has been failing on CI for several weeks but Rhub GCC 12 seems to be successful. Example for last nightly: https://github.com/apache/arrow/actions/runs/24381689114/job/71206402529

Should we still remove that one too?

I think so - my reasoning was that the job's purpose is to track CRAN builds, but they no longer run on GCC12 anyway, and when we do follow-up ticket #49738 (which should be unblocked soon) we'll have the GCC15 jobs we need

[raulcd]

ok, then temporarily disabling both builds sounds good to me! Thanks @thisisnic

[conbench-apache-arrow]

After merging your PR, Conbench analyzed the 3 benchmarking runs that have been run so far on merge-commit 0fb2c8e.

There were no benchmark performance regressions. 🎉

The full Conbench report has more details. It also includes information about 1 possible false positive for unstable benchmarks that are known to sometimes produce them.