debugger: Mark DebugAdapterBinary::program as optional (#32534)

This allows us to support debugging with a debug adapter not managed by
Zed. Note that this is not a user facing change, as DebugAdapterBinary
is used to determine how to spawn a debugger. Thus, this should not
break any configs or anything like that.

Closes #ISSUE

Release Notes:

- N/A
6c4728f00fPiotr Osiewicz committed on 6/11/2025, 10:38:12 AM· committed by GitHubparenta3cc063
14 files changedLine totals unavailable