CurlDownloadStrategy: Ignore invalid last-modified header values

- Some download locations return a non-standard formatting of date string for the `Last-Modified` header.
  This causes `Time.parse` to blow up. The user sees `error: argument out of range`.
- In this commit we handle the error and return nil, which `filter_map` (equivalent to `.map.compact`) gets rid of and then `time.last` is as normal.
- Fixes https://github.com/Homebrew/brew/issues/ 17556.

Library/Homebrew/download_strategy.rb

@@ -520,8 +520,11 @@ class CurlDownloadStrategy < AbstractFileDownloadStrategy
 
     time =  parsed_headers
             .flat_map { |headers| [*headers["last-modified"]] }
-           .map { |t| t.match?(/^\d+$/) ? Time.at(t.to_i) : Time.parse(t) }
+            .filter_map do |t|
-           .last
+              t.match?(/^\d+$/) ? Time.at(t.to_i) : Time.parse(t)
+            rescue ArgumentError
+              nil
+            end
 
     file_size = parsed_headers
                 .flat_map { |headers| [*headers["content-length"]&.to_i] }
@@ -530,7 +533,7 @@ class CurlDownloadStrategy < AbstractFileDownloadStrategy
     is_redirection = url != final_url
     basename = filenames.last || parse_basename(final_url, search_query: !is_redirection)
 
-    @resolved_info_cache[url] = [final_url, basename, time, file_size, is_redirection]
+    @resolved_info_cache[url] = [final_url, basename, time.last, file_size, is_redirection]
   end
 
   def _fetch(url:, resolved_url:, timeout:)