fix(builtin): default STDOUT_CAPTURE_IS_NOT_AN_OUTPUT to falsey

[ptarjan]

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?

line 358: STDOUT_CAPTURE_IS_NOT_AN_OUTPUT: unbound variable

Issue Number: N/A

What is the new behavior?

Silence

Does this PR introduce a breaking change?

• Yes
• No

Other information

I couldn't figure out a way to construct a test for this. I tried a syntax error in a JS file as well a using fail.spec.js. Neither of them gave the behavior my user was seeing inside our company. But once I applied this patch, their error message went away.