[r/ci] Try to unbreak r-valgrind CI

[johnkerl]

Issue and/or context: #3315 [sc-59088]

Changes: With #3313 in place to avoid the problematic (default) truncation to 13 lines of output, I ran https://github.com/single-cell-data/TileDB-SOMA/actions/runs/11744677785/job/32720341469 and saw

2024-11-08T15:36:21.1886016Z   **4849** new/new[] failed and should throw an exception, but Valgrind
2024-11-08T15:36:21.1887203Z   **4849**    cannot throw exceptions and so is aborting instead.  Sorry.

I'm imitating a memory config from other R CI YAMLs in our project in hopes this will help.

Notes for Reviewer:

Manual r-valgrind run (since that CI doesn't run on every PR):
https://github.com/single-cell-data/TileDB-SOMA/actions/runs/11745362897

Note we have another active R CI failure (unrelated) #3314 which is muddying the waters.

[johnkerl]

The manual run of r-valgrind CI ran successfully to completion:
https://github.com/single-cell-data/TileDB-SOMA/actions/runs/11745362897/job/32722604067