copyApps: workaround for macOS 26.3 signature bug

[jbellerb]

Description

macOS throws a code signing error when the modification time on an app is set to 1. This seems to have started on macOS 26.3, but I'm not fully sure. Hitting this is uncommon. macOS caches signatures, so apps that were opened prior to updating macOS continue to work. I ran into this because Ghostty 1.3.0 added a new signature to their bundle.

Checklist

• Change is backwards compatible.

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