Spotted on main: https://github.com/coder/coder/actions/runs/14179449567/job/39721999486
```
=== FAIL: coderd TestOIDCDomainErrorMessage/MalformedEmailErrorOmitsDomains (0.01s)
==================
WARNING: DATA RACE
Read at 0x00c060b54e68 by goroutine 296485:
golang.org/x/oauth2.(*Config).Exchange()
/home/runner/go/pkg/mod/golang.org/x/oauth2@v0.28.0/oauth2.go:228 +0x1d8
github.com/coder/coder/v2/coderd.(*OIDCConfig).Exchange()
<autogenerated>:1 +0xb7
github.com/coder/coder/v2/coderd.New.func11.12.1.2.ExtractOAuth2.1.1()
/home/runner/work/coder/coder/coderd/httpmw/oauth2.go:168 +0x7b5
net/http.HandlerFunc.ServeHTTP()
/opt/hostedtoolcache/go/1.24.1/x64/src/net/http/server.go:2294 +0x47
[...]
Previous write at 0x00c060b54e68 by goroutine 55730:
github.com/coder/coder/v2/coderd/coderdtest/oidctest.(*FakeIDP).SetRedirect()
/home/runner/work/coder/coder/coderd/coderdtest/oidctest/idp.go:1280 +0x1e6
github.com/coder/coder/v2/coderd/coderdtest/oidctest.(*FakeIDP).LoginWithClient()
/home/runner/work/coder/coder/coderd/coderdtest/oidctest/idp.go:494 +0x170
github.com/coder/coder/v2/coderd/coderdtest/oidctest.(*FakeIDP).AttemptLogin()
/home/runner/work/coder/coder/coderd/coderdtest/oidctest/idp.go:479 +0x624
github.com/coder/coder/v2/coderd_test.TestOIDCDomainErrorMessage.func3()
/home/runner/work/coder/coder/coderd/userauth_test.go:2041 +0x1f2
```
As seen, this race was caused by sharing a `*oidctest.FakeIDP` between test cases. The fix is to simply do the setup twice.
```
$ go test -race -run "TestOIDCDomainErrorMessage" github.com/coder/coder/v2/coderd -count=100
ok github.com/coder/coder/v2/coderd 7.551s
````
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