Fix for failing R benchmarks - cast all decimal32/64 to decimal128

[thisisnic]

Benchmarks are failing (apache/arrow#46716) because decimal32 and decimal64 types have been implemented in Arrow but not Parquet, so when this type is being written to disk there is an error. This PR upcasts any decimal32/64 instances to decimal128 when writing to Parquet in R.

Haven't been able to test this out locally, so I've gone for a bit of an overkill approach and used this in calls to write_parquet().

[jonkeane]

Thanks for this. This looks good (though we should remove the addition in bm-write-file.R)

[thisisnic]

Cheers @jonkeane, have now removed a couple of the additions there.

[jonkeane]

😢 Apparently I can't approve the CI runs, nor merge to this repo. @assignUser could you assist?

[assignUser]

I don't have write access either, I'll request that asap

[assignUser]

Ugh, looks like there are multiple issues that need to be fixed unrelated to the PR... I assume the env in the actual benchmark runner is pinned better than here?

[thisisnic]

Ugh, looks like there are multiple issues that need to be fixed unrelated to the PR... I assume the env in the actual benchmark runner is pinned better than here?

Unsure sorry. Mind approving the workflows again so I can check my changes worked for at least the tests bit for now?