Avoid throwing when workers shutdown on Windows

[Drvi]

When porting a private package to Julia 1.12, I consistently ran into issues when all the tests pass but the test run failed with an error pointing to worker termination:

ERROR: LoadError: TaskFailedException
    nested task error: TaskFailedException
    Stacktrace:
      [1] #wait#582
        @ .\task.jl:363 [inlined]
      [2] wait
        @ .\task.jl:360 [inlined]
      [3] fetch
        @ .\task.jl:554 [inlined]
      [4] wait
        @ .\packages\ReTestItems\rFUty\src\workers.jl:145 [inlined]
      [5] close(w::ReTestItems.Workers.Worker)
        @ ReTestItems.Workers .\packages\ReTestItems\rFUty\src\workers.jl:140
      [6] manage_worker(worker::ReTestItems.Workers.Worker, proj_name::String, testitems::ReTestItems.TestItems, testitem::TestItem, cfg::ReTestItems._Config; worker_num::Int64)
        @ ReTestItems .\packages\ReTestItems\rFUty\src\ReTestItems.jl:753
        ...
        nested task error: IOError: kill: permission denied (EACCES)
        Stacktrace:
         [1] kill(p::Base.Process, signum::Int64)
           @ Base .\process.jl:627
         [2] terminate!(w::ReTestItems.Workers.Worker, from::Symbol)
           @ ReTestItems.Workers .\packages\ReTestItems\rFUty\src\workers.jl:87
         [3] process_responses(w::ReTestItems.Workers.Worker, ev::Base.Event)
           @ ReTestItems.Workers .\packages\ReTestItems\rFUty\src\workers.jl:272
         [4] (::ReTestItems.Workers.var"#18#19"{ReTestItems.Workers.Worker, Base.Event})()
           @ ReTestItems.Workers .\packages\ReTestItems\rFUty\src\workers.jl:206
        caused by: EOFError: read end of file
        Stacktrace:
         [1] read(this::Sockets.TCPSocket, ::Type{UInt8})
           @ Base .\stream.jl:1012
         [2] deserialize
           @ .\stdlib\v1.12\Serialization\src\Serialization.jl:851 [inlined]
         [3] deserialize(s::Sockets.TCPSocket)
           @ Serialization .\stdlib\v1.12\Serialization\src\Serialization.jl:838
         [4] process_responses(w::ReTestItems.Workers.Worker, ev::Base.Event)
           @ ReTestItems.Workers .\packages\ReTestItems\rFUty\src\workers.jl:254
         [5] (::ReTestItems.Workers.var"#18#19"{ReTestItems.Workers.Worker, Base.Event})()
           @ ReTestItems.Workers .\packages\ReTestItems\rFUty\src\workers.jl:206
...and 4 more exceptions.
Stacktrace:
  [1] sync_end(c::Channel{Any})
  ...

The issue seems to be that when a worker shuts down, the managing task gets an EOFError when listening for messages to deserialize from the worker, and then in a catch block it tries to terminate! the already-shut-down worker, but it seems that marking the worker as done is racy (i.e. its process_running(p) can still return true at this point), so we end up trying to kill an exited worker, which results in an access violation error on Windows.

With this patch, the issue no longer reproduces.
I also fixed a junit_xml.jl tests since some of the error messages changed on Julia 1.12, and I bumped the CI Julia version from '~1.12.0-rc1' to '1.12'

[quinnj]

not sure what the CI failure is, but this LGTM