Parallel creation of parameterized reports fails due to file conflicts

Bug description

I'm trying to generate parameterized reports in parallel on Ubuntu 22.04 LTS using quarto=1.2.335. For this, I'm using the following test.qmd file:

---
title: paralell report generation fails
params:
  counter: 1
format:
  html:
    embed-resources: true
---

\```{r}
Sys.sleep(5)
\```

This is report number `r params$counter`

Generating both report out1.html and out2.html works fine when running sequentially:

quarto render test.qmd -P counter:1 --output out1.html
quarto render test.qmd -P counter:2 --output out2.html

However, when I try to run them in parallel I get:

quarto render test.qmd -P counter:1 --output out1.html &;
quarto render test.qmd -P counter:2 --output out2.html
# Error in readLines(con, warn = FALSE) : cannot open the connection
# Calls: .main ... partition_yaml_front_matter -> grep -> is.factor -> read_utf8 -> readLines

I suspect this is because both reports store their temporary files in test_files/. Wouldn't it make more sense to use the output file base as directory, because this should not conflict?

Checklist

• Please include a minimal, fully reproducible example in a single .qmd file? Please provide the whole file rather than the snippet you believe is causing the issue.
• Please format your issue so it is easier for us to read the bug report.
• Please document the RStudio IDE version you're running (if applicable), by providing the value displayed in the "About RStudio" main menu dialog?
• Please document the operating system you're running. If on Linux, please provide the specific distribution.

Start with the provided test.qmd and run the two quarto render commands concurrently on Ubuntu 22.04 with quarto 1.2.335. Inspect how the parallel renders use test_files/ and reproduce the readLines failure; done means both out1.html and out2.html render successfully without conflicting temporary files.