[bugfix] capturing package names crashes at runtime

[keynmol]

This is the minimal reproduction and fix for #54.

General idea is just to forget any symbols that have a Package flag.

While this fixes the repro and is small enough to seem generic enough, I don't think it does a great job in terms of failure rendering:

[info] - Capturing package names correctly *** FAILED ***
[info]   assertion failed
[info]   
[info]   cats.data.Chain(1, 2, 3).size != 3
[info]   |         |              |    |
[info]   |         |              3    false
[info]   |         cats.data.Chain$@34f86192
[info]   List(1, 2, 3)
[info]     com.eed3si9n.expecty.ExpectyBase$ExpectyListener.expressionRecorded(Expecty.scala:41)
[info]     com.eed3si9n.expecty.RecorderRuntime.recordExpression(RecorderRuntime.scala:40)
[info]     foo.ExpectyScala3Test$.$init$$$anonfun$4(ExpectyScala3Test.scala:73)

Although I can be persuaded that it's the way it's supposed to work, given the nature of power assertions :)

@eed3si9n @Baccata if you agree that it's a fix, I say we merge and release, and create another issue for all the strange Scala 3 only fixes we had to do - feels like we need a much more systematic approach for those things.

[Baccata]

I personally agree with the approach and the proposed plan 👍