bug(installer): foundryup should only download when updates are available

[gosuto-inzasheru]

Component

Foundryup

Have you ensured that all of these are up to date?

• Foundry
• Foundryup

What version of Foundry are you on?

forge 0.2.0 (00efa0d 2024-12-09T00:29:01.805479000Z)

What command(s) is the bug in?

foundryup

Operating System

macOS (Apple Silicon)

Describe the bug

currently, running foundryup twice in a row will trigger a new download/installation of exactly the same version it installed previously. a lot of resources could be saved by comparing commits, and simply printing something along the lines of "Foundry is already up-to-date (00efa0d 2024-12-09T00:29:01.805479000Z)"

[zerosnacks]

cc @grandizzy possibly related to signed releases? we can then just check the local hash against the hash of the binary being pulled in