Stacktraces from the repl aren't shortened from within @testsets

[IanButterworth]

This looks good

julia> error()
ERROR:
Stacktrace:
 [1] error()
   @ Base ./error.jl:45
 [2] top-level scope
   @ REPL[1]:1

julia> @time error()
ERROR:
Stacktrace:
 [1] error()
   @ Base ./error.jl:45
 [2] macro expansion
   @ ./timing.jl:611 [inlined]
 [3] top-level scope
   @ ./REPL[4]:1

But I believe everything past the 4th frame here should be hidden as repl internals.

julia> using Test

julia> @testset begin
       error()
       end
test set: Error During Test at REPL[3]:1
  Got exception outside of a @test

  Stacktrace:
    [1] error()
      @ Base ./error.jl:45
    [2] top-level scope
      @ REPL[3]:2
    [3] macro expansion
      @ ~/Documents/GitHub/julia/usr/share/julia/stdlib/v1.12/Test/src/Test.jl:1724 [inlined]
    [4] macro expansion
      @ REPL[3]:2 [inlined]
    [5] __repl_entry_eval_expanded_with_loc(mod::Module, ast::Any, toplevel_file::Ref{Ptr{UInt8}}, toplevel_line::Ref{Int32})
      @ REPL ~/Documents/GitHub/julia/usr/share/julia/stdlib/v1.12/REPL/src/REPL.jl:341
    [6] #invokelatest#1
      @ ./essentials.jl:1056 [inlined]
    [7] invokelatest
      @ ./essentials.jl:1052 [inlined]
    [8] toplevel_eval_with_hooks(mod::Module, ast::Any, toplevel_file::Any, toplevel_line::Any)
      @ REPL ~/Documents/GitHub/julia/usr/share/julia/stdlib/v1.12/REPL/src/REPL.jl:348
    [9] toplevel_eval_with_hooks(mod::Module, ast::Any, toplevel_file::Any, toplevel_line::Any)
      @ REPL ~/Documents/GitHub/julia/usr/share/julia/stdlib/v1.12/REPL/src/REPL.jl:352
   [10] toplevel_eval_with_hooks
      @ ~/Documents/GitHub/julia/usr/share/julia/stdlib/v1.12/REPL/src/REPL.jl:345 [inlined]
   [11] eval_user_input(ast::Any, backend::REPL.REPLBackend, mod::Module)
      @ REPL ~/Documents/GitHub/julia/usr/share/julia/stdlib/v1.12/REPL/src/REPL.jl:370
   [12] repl_backend_loop(backend::REPL.REPLBackend, get_module::Function)
      @ REPL ~/Documents/GitHub/julia/usr/share/julia/stdlib/v1.12/REPL/src/REPL.jl:482
   [13] start_repl_backend(backend::REPL.REPLBackend, consumer::Any; get_module::Function)
      @ REPL ~/Documents/GitHub/julia/usr/share/julia/stdlib/v1.12/REPL/src/REPL.jl:467
   [14] start_repl_backend
      @ ~/Documents/GitHub/julia/usr/share/julia/stdlib/v1.12/REPL/src/REPL.jl:464 [inlined]
   [15] run_repl(repl::REPL.AbstractREPL, consumer::Any; backend_on_current_task::Bool, backend::Any)
      @ REPL ~/Documents/GitHub/julia/usr/share/julia/stdlib/v1.12/REPL/src/REPL.jl:690
   [16] run_repl(repl::REPL.AbstractREPL, consumer::Any)
      @ REPL ~/Documents/GitHub/julia/usr/share/julia/stdlib/v1.12/REPL/src/REPL.jl:676
   [17] run_std_repl(REPL::Module, quiet::Bool, banner::Symbol, history_file::Bool)
      @ Base ./client.jl:490
   [18] #invokelatest#1
      @ ./essentials.jl:1056 [inlined]
   [19] invokelatest
      @ ./essentials.jl:1052 [inlined]
   [20] run_main_repl(interactive::Bool, quiet::Bool, banner::Symbol, history_file::Bool)
      @ Base ./client.jl:511
   [21] repl_main
      @ ./client.jl:593 [inlined]
   [22] _start()
      @ Base ./client.jl:568
Test Summary: | Error  Total  Time
test set      |     1      1  0.5s
ERROR: Some tests did not pass: 0 passed, 0 failed, 1 errored, 0 broken.

julia>

Seems to be related to #49451