fix: don't escape dash in define regex

[jonaskuske]

Description

fix #9964

Additional context

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What is the purpose of this pull request?

• [x] Bug fix
• [ ] New Feature
• [ ] Documentation update
• [ ] Other

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• [x] Read the Contributing Guidelines.
• [x] Read the Pull Request Guidelines and follow the Commit Convention.
• [x] Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• [x] Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• [x] Ideally, include relevant tests that fail without this PR but pass with it.

[patak-dev]

As you explained in https://github.com/vitejs/vite/issues/9964#issuecomment-1235534424, the define feature needs to work both during build and dev. So we can't allow dashes if they are only going to work during build. I think your recommendations in #9964 were on point, and we should keep define as is.

[jonaskuske]

👍🏻👍🏻

I still think that constructing an invalid Regex isn't really sound though. What do you think about fixing the Regex so it doesn't throw an obscure error anymore, but printing a warning if a define key contains a character that can't be part of a variable/identifier?

[patak-dev]

@jonaskuske that sounds like a great improvement 👍🏼