#parse_curl_output: increase default max_iterations

The `max_iterations` value in `#parse_curl_output` is only intended
to prevent its `while` loop from potentially turning into an endless
loop. This should only come into play in exceptional circumstances
but the current default value (5) is low enough that we're seeing it
under normal circumstances.

`#parse_curl_output` isn't intended to restrict the number of
redirections (this should be done using the `--max-redirs` option in
`curl) but it's effectively doing this in rare cases due to the low
`max_iterations` default. This is a problem because `curl` can
successfully return a response only to have `#parse_curl_output`
error in relation to `max_iterations`.

Originally the code in `#parse_curl_output` was used in the context
of livecheck, where it's not a huge issue if a check fails. However,
now the `#parse_curl_output` method is used in important parts of
brew like `#curl_download`. We've received a report of a download
failing with the "Too many redirects (max = 5)` error, effectively
preventing the user from installing a formula [from a third-party
tap].

Until we can come up with a more adaptive way of bounding this
`while` loop, I think we should simply raise the default to something
that's less likely to be encountered under normal circumstances
(e.g., 25).

Library/Homebrew/utils/curl.rb

@@ -400,7 +400,7 @@ module Utils
     # @return [Hash] A hash containing an array of response hashes and the body
     #   content, if found.
     sig { params(output: String, max_iterations: Integer).returns(T::Hash[Symbol, T.untyped]) }
-    def parse_curl_output(output, max_iterations: 5)
+    def parse_curl_output(output, max_iterations: 25)
       responses = []
 
       iterations = 0