[C++] c-ares download URL is stale?

[jonkeane]

Describe the bug, including details regarding any error messages, version, and platform.

I noticed the following error in test-r-offline-maximal, but this is really about the source of c-ares source when building C++.

> source('R/install-arrow.R'); create_package_with_all_dependencies(dest_file = 'arrow_with_deps.tar.gz', source_file = "arrow_16.1.0.9000.tar.gz")
Error in download.file("https://c-ares.haxx.se/download/c-ares-1.17.2.tar.gz",  : 
  cannot open URL 'https://c-ares.haxx.se/download/c-ares-1.17.2.tar.gz'
Calls: create_package_with_all_dependencies ... source -> withVisible -> eval -> eval -> download.file
In addition: Warning message:
In download.file("https://c-ares.haxx.se/download/c-ares-1.17.2.tar.gz",  :
  cannot open URL 'https://c-ares.org/download/c-ares-1.17.2.tar.gz': HTTP status was '404 Not Found'
Execution halted

Looking at https://c-ares.org/download/ the linked URLs did recently change to be of the form https://github.com/c-ares/c-ares/releases/download/cares-1_17_2/c-ares-1.17.2.tar.gz

We could change this in ThirdpartyToolchain.cmake and versions.txt (though we would need to do a bit of substituting of . to _ to form the URL correctly. But it might be worth confirming this is the right URL now? I searched a bit for this in the c-ares repo and couldn't find anything, but I might have had the wrong terms

Component(s)

C++

[kou]

Issue resolved by pull request 42250
#42250