[R] `read_csv_arrow()`'s `timestamp_parsers` parameter is a bit light on documentation and doesn't appear to do anything

### Describe the bug, including details regarding any error messages, version, and platform.

``` r
library(arrow)
df <- data.frame(time = "2023-01-16 19:47:57")
dst_dir <- tempfile()
dir.create(dst_dir)
dst_file <- file.path(dst_dir, "data.csv")
write.table(df, sep = ",", dst_file, row.names = FALSE, quote = FALSE)

read_csv_arrow(dst_file, timestamp_parsers = c(TimestampParser$create(format = "%m-%d-%y")))
#> time
#> 1 2023-01-16 19:47:57
```

I'm not sure how exactly it's supposed to work, but it appears not to do anything, and neither the docs nor error messages are enough to tell me what I'm supposed to be doing/seeing here.

### Component(s)

R