Issue fetching deps with authentication on hex version 2.4.0

[NexPB]

Our CI for is getting the following errors (same issue exists locally):

02:33:43.187 [error*** Task #PID<0.330.0> started from :hex_fetcher terminating
** (RuntimeError) Failed to exchange API key for OAuth token: :exchange_failed
    (hex 2.4.0) lib/hex/repo.ex:306: Hex.Repo.build_hex_core_config/3
    (hex 2.4.0) lib/hex/repo.ex:202: Hex.Repo.get_package/3
    (hex 2.4.0) lib/hex/registry/server.ex:331: anonymous fn/3 in Hex.Registry.Server.prefetch_online/2
    (elixir 1.19.5) lib/task/supervised.ex:105: Task.Supervised.invoke_mfa/2
    (elixir 1.19.5) lib/task/supervised.ex:40: Task.Supervised.reply/4
Function: #Function<19.81948766/0 in Hex.Registry.Server.prefetch_online/2>
    Args: [***
** (exit) exited in: GenServer.call(Hex.Registry.Server, {:versions, "oban", "oban_pro"*** 60000)
    ** (EXIT) time out
    (elixir 1.19.5) lib/gen_server.ex:1142: GenServer.call/3
    (hex 2.4.0) lib/hex/remote_converger.ex:638: Hex.RemoteConverger.verify_dep/3
    (elixir 1.19.5) lib/enum.ex:966: anonymous fn/3 in Enum.each/2
    (stdlib 7.2) maps.erl:894: :maps.fold_1/4
    (elixir 1.19.5) lib/enum.ex:2532: Enum.each/2
    (hex 2.4.0) lib/hex/remote_converger.ex:54: Hex.RemoteConverger.converge/2
    (mix 1.19.5) lib/mix/dep/converger.ex:137: Mix.Dep.Converger.all/4
    (mix 1.19.5) lib/mix/dep/converger.ex:93: Mix.Dep.Converger.converge/4

It's crashing at oban and oban_pro which does have the following auth:

mix hex.repo add oban https://getoban.pro/repo --fetch-public-key ${{ env.OBAN_KEY_FINGERPRINT }} --auth-key ${{ env.OBAN_AUTH_KEY }}

[GriffinHeart]

@NexPB you might need to now add --no-oauth-exchange option https://github.com/hexpm/hex/blob/main/lib/mix/tasks/hex.repo.ex#L48, it fixed it for us

[ericmj]

I can't reproduce the mix hex.repo add and --no-oauth-exchange is already the default so it shouldn't make a difference.

But I found an issue when loading a config from <2.4.0, so if you called mix hex.repo add before you updated then you would see the error in this issue. Fixing this in #1120.

The workaround until #1120 is shipped should be to run again mix hex.repo add again to get a repo config with the correct defaults.