Git: Actually time out in 5 seconds

[3v0k4]

Description

Fixes #327

I considered using

pid = Process.spawn(*args, [:out, :err] => File::NULL, pgroup: true)
safe_kill(-pid)

but wanted to keep Windows compatibility (at the cost of leaking potential grandchildren processes).

See also: https://github.com/main-branch/process_executer/blob/4cc69036bbdda383a8ecb50bd63b19f96303203a/lib/process_executer/commands/spawn_with_timeout.rb

Checks

• I added the changes to the UNRELEASED section of the CHANGELOG.md, including the needed bump (i.e., patch, minor, major)
• I followed the architecture outlined below for RSpec in Queue Mode:
  • Pure: lib/knapsack_pro/pure/queue/rspec_pure.rb contains pure functions that are unit tested.
  • Extension: lib/knapsack_pro/extensions/rspec_extension.rb encapsulates calls to RSpec internals and is integration and E2E tested.
  • Runner: lib/knapsack_pro/runners/queue/rspec_runner.rb invokes the pure code and the extension to produce side effects, which are integration and E2E tested.