GH-38766: [R] Add timeout option to try_download (#38767)

### Rationale for this change

The download of static libraries during installation might be causing an install failure: https://www.r-project.org/nosvn/R.check/r-devel-windows-x86_64/arrow-00install.html

### What changes are included in this PR?

The timeout value is temporarily increased according to guidance in the help for `download.file()`

### Are these changes tested?

Yes, this code runs during install for at least some CI jobs (also used to download cmake)

### Are there any user-facing changes?

No
* Closes: #38766

Lead-authored-by: Dewey Dunnington <dewey@fishandwhistle.net>
Co-authored-by: Dewey Dunnington <dewey@voltrondata.com>
Signed-off-by: Jacob Wujciak-Jens <jacob@wujciak.de>

r/tools/nixlibs.R

@@ -79,9 +79,15 @@ find_latest_nightly <- function(description_version,
 }
 
 try_download <- function(from_url, to_file, hush = quietly) {
+  # We download some fairly large files, so ensure the timeout is set appropriately.
+  # This assumes a static library size of 100 MB (generous) and a download speed
+  # of 1 MB/s (slow).
+  opts <- options(timeout = max(100, getOption("timeout")))
+  on.exit(options(opts))
+
   status <- try(
     suppressWarnings(
-      download.file(from_url, to_file, quiet = hush)
+      download.file(from_url, to_file, quiet = hush, mode = "wb")
     ),
     silent = hush
   )