[llvm] [Dexter] Replace DAP "initialized" timeout with a warning (PR #174198)

[Jason Molenda via llvm-commits]

jasonmolenda wrote:

Thanks for digging in to this Stephen, I saw the flakey dexter fails on the CIs but hadn't dug in to figure out what the cause was at all yet.  The performance of the CI can be surprisingly different from any typical desktop, often running in VMs on possibly multi-use machines, there's a lot of different configurations of these.

https://github.com/llvm/llvm-project/pull/174198