Mistake in Destructor example

[timmyjose]

Location: https://github.com/rougier/CPP-Crash-Course?tab=readme-ov-file#32destructor

Issue: In main, that should be Foo foo; instead of Foo foo(); (which will give a "most vexing parse" error").

[rougier]

Thanks. Can you make a PR?

[timmyjose]

@rougier Done! Opened PR #6