## Summary
`collect.FailNow()` should exit goroutine without a panic to be usable
with `require` package.
## Changes
`collect.FailNow()` just does `runtime.Goexit()` instead of `panic()`.
For example `FailNow()` from `testing` package [behaves
similarly](https://cs.opensource.google/go/go/+/refs/tags/go1.21.2:src/testing/testing.go;l=973).
## Motivation
I just want `require` package to be usable with `EventuallyWithT` e.g. I
want this example to pass but it panics:
```go
package main
import (
"testing"
"time"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
func TestRequireEventuallyWithT(t *testing.T) {
state := 0
require.EventuallyWithT(t, func(c *assert.CollectT) {
defer func() { state += 1 }()
require.True(c, state == 2)
}, 100*time.Millisecond, 10*time.Millisecond)
}
```
See https://go.dev/play/p/Oqd95IT7qxQ
## Related issues
Fixes https://github.com/stretchr/testify/issues/1396
Fixes https://github.com/stretchr/testify/issues/1457
Vladimir Kochnev
Alun Evans
Ivo van der Wijk
Nobuhiro MIKI
Cory Bennett
Julian Cooper
Will Faught
Anatoly Scheglov