Fixes #39229 - Add foreman_request_timeout setting to control Net::HTTP read timeout

[pablomh]

Problem

ForemanRequest uses a bare Net::HTTP instance whose read_timeout defaults to Ruby's hardcoded 60s. Under high-concurrency registration load this causes 500 errors when Foreman takes longer than 60s to process POST /register.

Fix

Introduces :foreman_request_timeout and documents it in settings.yml.example, then applies it to http.read_timeout in ForemanRequest#http_init when configured and greater than zero. The respond_to? guard preserves backward compatibility when the setting is absent.

subscription-manager's default server_timeout is 180s, so values above that are recommended to avoid cutting connections the client is still waiting on.

Fixes https://projects.theforeman.org/issues/39229

[pablomh]

CI failure: rake 13.4.2 regression (not related to this PR)

All test jobs fail with rake_test_loader: version unknown and exit code 1. The test runner never actually runs any tests.

Root cause: gem 'rake' in bundler.d/test.rb has no version constraint and no Gemfile.lock is committed, so CI resolves the latest version from rubygems.org. Rake 13.4.2 (released April 16) changed Rake::TestTask#option_list to append -v to the test command when verbose = true — previously this flag was not passed to the test runner. The new -v causes test-unit 3.7.7 to fail silently.

This affects all new PRs on smart-proxy, not just this one. PR #935 passed because its bundle cache still had rake 13.3.1.

Diff in lib/rake/testtask.rb (13.3.1 → 13.4.2):

# 13.3.1 — option_list never adds -v
def option_list
  (ENV["TESTOPTS"] || ENV["TESTOPT"] || ENV["TEST_OPTS"] || ENV["TEST_OPT"] || @options || "")
end

# 13.4.2 — now adds -v when verbose is true
def option_list(verbose: @verbose)
  opts = ENV["TESTOPTS"] || ENV["TESTOPT"] || ENV["TEST_OPTS"] || ENV["TEST_OPT"] || @options || ""
  if verbose && !opts.split.include?("-v")
    opts = opts.empty? ? "-v" : "#{opts} -v"
  end
  opts
end

Fix options:

• Pin gem 'rake', '< 13.4' in bundler.d/test.rb (workaround)
• Report the regression upstream to ruby/rake
• Or fix the test-unit interaction with -v if the issue is on that side

[ekohl]

Makes sense, but 1 minor comment inline.