Allow use of connection_pool 3.0 #393
Description
With the introduction of non-vendored net-http-persistent, vault.gemspec also got a restriction on connection_pool that prohibits the use of connection_pool 3.
I'm not sure if this restriction is intentional or not, as net-http-persistent upstream allows use of connection_pool 3.
Since sidekiq 8.1+ requires connection_pool 3, this results in a choice to either use vault 0.19.0 and sidekiq 8.1, but be limited to ruby 3.4, or use vault 0.20.0 and ruby 4.0, but be limited to sidekiq 8.0.
It would be nice to be able to use both ruby 4.0 and sidekiq 8.1 when vault is a dependency :)