Mangled test output on julia 1.11

[MarcMush]

I tried running the tests with juliaup on nightly, and the printlns seemed to be interlaced with the progressbars:

Testing original interface...
Progress: 100%|██████████████�T�e�s�t�i�n�g� �d�e�s�c� �a�n�d� �p�r�o�g�r�e�s�s� �b�a�r�
█████████████████| Time: 0:00:01
ComputTiensgt.i.n.g  1n0o0 %d|e�s�c� �a�n�d� �n�o� �p�r�o�g�r�e�s�s� �b�a�r�0:00:00
�██████████████████████████████████████████| Time: 0:00:01
 100% Time: 0:00:01
Testing tty width...

It also happens in CI and when building from source in WSL

versioninfo

julia> versioninfo()
Julia Version 1.12.0-DEV.88
Commit 2e9b0bbf4e (2024-02-27 02:42 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: Windows (x86_64-w64-mingw32)
  CPU: 12 × Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
  WORD_SIZE: 64
  LLVM: libLLVM-16.0.6 (ORCJIT, skylake)
Threads: 1 default, 0 interactive, 1 GC (on 12 virtual cores)

julia> versioninfo()
Julia Version 1.12.0-DEV.88
Commit 2e9b0bbf4e* (2024-02-27 02:42 UTC)
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: 12 × Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
  WORD_SIZE: 64
  LLVM: libLLVM-16.0.6 (ORCJIT, skylake)
Threads: 1 default, 0 interactive, 1 GC (on 12 virtual cores)

I can't reproduce it outside of tests:

julia> begin
       println("Testing original interface...")
       testfunc(107, 0.01, 0.01)

       println("Testing desc and progress bar")
       testfunc2(107, 0.01, 0.01, "Computing...", 50)
       println("Testing no desc and no progress bar")
       testfunc2(107, 0.01, 0.01, "", 0)
       end
Testing original interface...
Progress: 100%|█████████████████████████████████████████████████████████████████████████████████████████████████████████████████████| Time: 0:00:01
Testing desc and progress bar
Computing... 100%|██████████████████████████████████████████████████| Time: 0:00:01
Testing no desc and no progress bar
 100% Time: 0:00:01

adding sleep after the last next! fixes it:

function testfunc(n, dt, tsleep)
    p = Progress(n; dt=dt)
    for i = 1:n
        sleep(tsleep)
        next!(p)
    end
    sleep(tsleep)
end