Fail to run keyring tests

[adamcstephens]

As discussed in https://github.com/NixOS/nixpkgs/pull/394097. We've patched around this for now, but since you suggested this may be a bug I'm opening an issue here.

ok      github.com/foxboron/ssh-tpm-agent/contrib       0.002s
--- FAIL: TestNokey (0.00s)
    keyring_test.go:37: err: no such file or directory
--- FAIL: TestRemoveKey (0.00s)
    keyring_test.go:64: we can still read the key
--- FAIL: TestNokeyThreaded (0.00s)
    threadkeyring_test.go:45: err: no such file or directory
--- FAIL: TestRemoveKeyThreaded (0.00s)
    threadkeyring_test.go:75: we can still read the key
FAIL
FAIL    github.com/foxboron/ssh-tpm-agent/internal/keyring      0.004s

[Foxboron]

It was originally brought up in this PR. But as everything is passing on my end I didn't quite grok if it was an actual issue or not.

https://github.com/Foxboron/ssh-tpm-agent/pull/91

[Foxboron]

See: https://github.com/Foxboron/ssh-tpm-agent/pull/94#issuecomment-2932568075

You need to install the proper helpers for the test suite to run. Turns out this is not an upstream issue.

[Foxboron]

Closing this as this is not an ssh-tpm-agent issue.