ci: add test-all-solc-versions input to the core ci

[galargh]

• Because this PR includes a bug fix, relevant tests have been included.
• Because this PR includes a new feature, the change was previously discussed on an Issue or with someone from the team.
• I didn't do anything of this.

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This PR restores the ability to run the tests for all solc versions in CI on demand. It doesn't change the default of running the tests only for the compiler versions marked as latest.

Here's an example run - https://github.com/NomicFoundation/hardhat/actions/runs/10846884277

Note that it currently fails with OOM errors :( These are the standard machines sizes - https://docs.github.com/en/actions/using-github-hosted-runners/using-github-hosted-runners/about-github-hosted-runners#standard-github-hosted-runners-for-public-repositories Do you think we should act on it?

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Name	Status	Preview	Comments	Updated (UTC)
hardhat	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Sep 16, 2024 6:46pm

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Latest commit: 879918d

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[schaable]

I'm going to give this an approval because it looks good to my eyes, but you probably know a lot more about workflows than me, so I'd ask for another reviewer if you're not totally sure about the changes 😄