Revamp rollup.config.js

[xty]

This PR introduces the following improvements to the Rollup configuration file:

1. compress.warnings is not a valid Terser option, as can be seen in Terser's docs and type declarations. Therefore, it has been removed.
2. To minimize the likelihood of making similar mistakes, Intellisense has been enabled for rollup.config.js, as recommended in Rollup's docs.
3. Currrently, the makeExternalPredicate function involves a great deal of indirection in preparing the external object. The fact that Rollup can accept an array of RegExps as external has made this a lot more straightforward.

Checklist

• Have you added an explanation of what your changes do and why you'd like us to include them?
• Is there an existing issue for this PR?
• Have the files been linted and formatted?
• Have the docs been updated to match the changes in the PR?
• Have the tests been updated to match the changes in the PR?
• Have you run the tests locally to confirm they pass?

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[timdorr]

Thanks!