Potential issue when running go test -json

@flowchartsman is already working on this.

Since Mar 14, 2023.

Hey Mat, long time. Ran into a curious issue worth filing.

### Summary

Running `go test -json ...` and using this package reports incorrect test names in JSON events. This could very well be a bug in Go (test2json), but figured I'd start here because if I remove `is` and use regular std. lib primitives it reports the correct thing.

### Reproducible example

I noticed this happening in https://github.com/pressly/goose and put together a PR to showcase the problem.

In this commit I purposefully changed a test to trigger a failure. Note the name of the test is `TestNotAllowMissing`.

https://github.com/pressly/goose/pull/353/commits/9b7c7321bdbabb8307e71a40e0601d86b222d6ce#diff-080f0d7ba408eaf6181e1f61388995ebcd57fdd1468ffafffbf789176531418fR30

When I run `go test -v -json -count=1 ./tests/e2e -dialect=postgres` I happily get JSON output. But, the test name in the JSON event doesn't line up with the Output.

I was expecting Output that `is` prints to be associated with test named `TestNotAllowMissing`, but instead it was associated with another test named `TestMigrateFull`. (the name is non-deterministic, it changes between runs).

The raw output can be [found here ](https://github.com/pressly/goose/runs/6490014124?check_suite_focus=true#step:5:158). But I've copied and trimmed the relevant bits:

```
{"Test":"TestMigrateFull","Output":"\t\u001b[90mallow_missing_test.go:30: \u001b[39m7 != 8\n"}
{"Test":"TestNotAllowMissing","Output":"--- FAIL: TestNotAllowMissing (3.73s)\n"}
```

The first JSON event refers to `allow_missing_test.go:30`, in the code base the [call site on line 30](https://github.com/pressly/goose/blob/b44efc3a961c5c8be1876ba296f0ea6c7ef8cfdb/tests/e2e/allow_missing_test.go#L12-L30) is located within the test named: `TestNotAllowMissing`, but the test name is `TestMigrateFull`.

The second JSON event correctly outputs the failure under the test named `TestNotAllowMissing`.

This could very well be a bug in how go test prints JSON events, but I suspect it may be something within this library. I say this because if I remove `is` from that specific test (`TestNotAllowMissing`) I see the expected output associated with the correct Test name:

Raw output can be [found here](https://github.com/pressly/goose/runs/6490280411?check_suite_focus=true#step:5:160)

```
{"Test":"TestNotAllowMissing","Output":" allow_missing_test.go:35: got 7: want: 8\n"}
{"Test":"TestNotAllowMissing","Output":"--- FAIL: TestNotAllowMissing (2.81s)\n"}
```