Parse rds could avoid hitting disk

https://github.com/rstudio/plumber/blob/56a69494cf15c3c3ca0831a86a91ba033337206a/R/parse-body.R#L479

https://stackoverflow.com/a/67229892

```r
con <- rawConnection(rawvectpr)
value <- con |> gzcon() |> readRDS()
close(con)
```