make the `bun upgrade <package name>` error smarter

[RiskyMH]

trafficstars

What does this PR do?

fixes #20347 by not strictly checking 2nd+ index of argv and instead checking all argv and thus --bun is discarded.

also updates the tests so hopefully the other successful tests don't inflate bun's download numbers

• [ ] Documentation or TypeScript types (it's okay to leave the rest blank in this case)
• [ ] Code changes

How did you verify your code works?

manually ran bun-debug upgrade (and other variations) and it worked as expected

[robobun]

^{Updated 3:14 AM PT - Jun 13th, 2025}

:x: @RiskyMH, your commit a5d81c9815d9a3b4d5eabbc1f36d2cc0fad4ebd8 has 1 failures in Build #18614:

• test/js/bun/spawn/spawn.test.ts - 1 failing on 🪟 2019 x64-baseline
• test/js/bun/spawn/spawn.test.ts - 1 failing on 🪟 2019 x64

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🧪   To try this PR locally:

bunx bun-pr 20367

That installs a local version of the PR into your bun-20367 executable, so you can run:

bun-20367 --bun