Remove `TestIdentifier.SerializedForm` to simplify `TestIdentifier` implementation

[sbrannen]

Overview

With the release of JUnit 6.0, we may be able to safely remove org.junit.platform.launcher.TestIdentifier.SerializedForm.

Related Issues

• Reduce memory footprint #2460
• NullPointerException when deserializing TestIdentifier #3819

[mehulimukherjee]

Hi @sbrannen , I am really interested in working on this issue, could you please assign this to me?
Thank you,
Mehuli

[marcphilipp]

The idea is to remove TestIdentifier.SerializedForm along with the custom writeObject and readObject methods in TestIdentifier and increment TestIdentifier.serialVersionUID.

@mehulimukherjee I've assigned the issue to you now. Sorry for the delay! Since we want to relase 6.0.0-RC3 in the next few days and want to include this change, it's rather time-critical. If you don't have time to work on this in the next few days, I can take it on and we can find a different issue for you to work on.

[mehulimukherjee]

Thanks @marcphilipp , for assigning it to me, I will work on it, and create the PR by Monday eod.