feat(builtin): allow bundling ESM output with the pkg_npm rule

[SkaillZ]

PR Checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature (please, look at the "Scope of the project" section in the README.md file)
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• Other... Please describe:

What is the current behavior?

Issue Number: #2647

What is the new behavior?

An attribute has been added that allows generating ESM files.

Does this PR introduce a breaking change?

• Yes
• No

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[SkaillZ]

@googlebot I signed it!

[alexeagle]

thanks!

[alexeagle]

this is great, do you know why we need this flag though? we don't have flags for the other JS flavors. Would something go wrong if we just made this always true for everyone in the next release?

[SkaillZ]

Sorry for the late reply! I don't think it would break anything so I've removed the flag.

[alexeagle]

thanks!

[alexeagle]

I'm concerned about dropping JsModuleInfo - I'm pretty sure it's possible that we get a dep that has JS files only in that provider but not in either of these two you've added. I think we should have all three. Would be nice if there was a red test result on this PR making me more confident...

[SkaillZ]

I've added the JSModuleInfo back, but I'm not sure where this provider is created. If you could give me an example of a rule where it's used, I could add a test case with it as well.

[alexeagle]

thanks!