Testset in included files do not execute tests

MWE:

`foo.jl`

```julia
@testset "wat" begin
    @test 1 == 1
end
```

`runtests.jl`

```julia
module Tests

using ReTest

@testset "foo" begin
include("foo.jl")
end

end

Tests.runtests()
```

Yields:

```
        Pass
foo |      0
```

Removing the `@testset` in `foo.jl` makes the tests execute.

This is on Julia v1.8 using ReTest v0.3.2.