misleading corpus_install() message "no info file"

The GermaParl v2.1.0 tarball available at Zenodo includes an info.md file, but screen output reports that it is not available. 

```r
library(cwbtools)
corpus_install(doi = "https://doi.org/10.5281/zenodo.12794676")
```

! no info file

This is misleading or wrong: The info file is there, this works:

```r
corpus("GERMAPARL2") %>% show_info()
```