Dashboard generation failing due to missing dependency 'readr'

See eg https://github.com/ursacomputing/crossbow/actions/runs/10677794014/job/29593573594

```
 processing file: crossbow-nightly-report.qmd
1/24                  
2/24 [setup]          
Error in `library()`:
! there is no package called 'readr'
Backtrace:
 1. base::library(readr)
```

cc @assignUser 