Deal with old failing weeks

[jonthegeek]

This fails:

tidytuesdayR::tt_load(2018, 7)
#> --- Compiling #TidyTuesday Information for 2018-05-14 ----
#> --- There is 1 file available ---
#> --- Starting Download ---
#> 
#>  Downloading file 1 of 1: `week7_starwars.csv`
#> Error in nchar(x, "width"): invalid multibyte string, element 1

^{Created on 2023-05-19 with reprex v2.0.2}

That week doesn't have a README for whatever reason, which I think is the source of the issue.

We should harden tidytuesdayR to deal with issues over in the main repo. If it can still get the data, do at least that much, and probably inform the user about any other specific strangeness.