CI failure on Base Windows CI sometimes

[KristofferC]

This test should probably be written in a way that gives a better error message when it fails:

Downloads                                       (12) \|         failed at 2025-07-12T10:05:55.709
--
  | Test Failed at C:\buildkite-agent\builds\win2k22-amdci6-7\julialang\julia-release-1-dot-12\julia-004c1a2a2c\share\julia\stdlib\v1.12\Downloads\test\runtests.jl:557
  | Expression: resp isa Response
  | Evaluated: Downloads.RequestError("https://untrusted-root.badssl.julialang.org", 28, "Failed to connect to untrusted-root.badssl.julialang.org port 443 after 21057 ms: Could not connect to server", Downloads.Response("https", "https://untrusted-root.badssl.julialang.org/", 0, "", Pair{String, String}[])) isa Downloads.Response
  |  
  | Error During Test at C:\buildkite-agent\builds\win2k22-amdci6-7\julialang\julia-release-1-dot-12\julia-004c1a2a2c\share\julia\stdlib\v1.12\Downloads\test\runtests.jl:558
  | Test threw exception
  | Expression: resp.status == 200
  | FieldError: type Downloads.RequestError has no field `status`
  | Stacktrace:
  | [1] getproperty(x::Downloads.RequestError, f::Symbol)
  | @ Base .\Base_compiler.jl:54
  | [2] macro expansion
  | @ C:\buildkite-agent\builds\win2k22-amdci6-7\julialang\julia-release-1-dot-12\julia-004c1a2a2c\share\julia\stdlib\v1.12\Test\src\Test.jl:677 [inlined]
  | [3] macro expansion
  | @ C:\buildkite-agent\builds\win2k22-amdci6-7\julialang\julia-release-1-dot-12\julia-004c1a2a2c\share\julia\stdlib\v1.12\Downloads\test\runtests.jl:558 [inlined]
  | [4] macro expansion
  | @ C:\buildkite-agent\builds\win2k22-amdci6-7\julialang\julia-release-1-dot-12\julia-004c1a2a2c\share\julia\stdlib\v1.12\Test\src\Test.jl:1776 [inlined]
  | [5] macro expansion
  | @ C:\buildkite-agent\builds\win2k22-amdci6-7\julialang\julia-release-1-dot-12\julia-004c1a2a2c\share\julia\stdlib\v1.12\Downloads\test\runtests.jl:545 [inlined]
  | [6] macro expansion
  | @ C:\buildkite-agent\builds\win2k22-amdci6-7\julialang\julia-release-1-dot-12\julia-004c1a2a2c\share\julia\stdlib\v1.12\Test\src\Test.jl:1776 [inlined]
  | [7] macro expansion
  | @ C:\buildkite-agent\builds\win2k22-amdci6-7\julialang\julia-release-1-dot-12\julia-004c1a2a2c\share\julia\stdlib\v1.12\Downloads\test\runtests.jl:534 [inlined]
  | [8] macro expansion
  | @ C:\buildkite-agent\builds\win2k22-amdci6-7\julialang\julia-release-1-dot-12\julia-004c1a2a2c\share\julia\stdlib\v1.12\Test\src\Test.jl:1776 [inlined]
  | [9] top-level scope
  | @ C:\buildkite-agent\builds\win2k22-amdci6-7\julialang\julia-release-1-dot-12\julia-004c1a2a2c\share\julia\stdlib\v1.12\Downloads\test\runtests.jl:4