Fix #2991

[MoonCoral]

Closes #2991

Only comments have isSilent as far as I could see. No comment should cause a parent to be printed in the 'referenced' case.
Thus I'm not even sure what the condition I deleted aimed to achieve.

Test is based on the snipped posted in #2991. css-3.css contained an empty @ rule, I assume to bypass the issue raised in #2991.

[MoonCoral]

Test failure seems to be a change of formatting of an error message in node 16. I don't see any relation to my changes.

 - /home/runner/work/less.js/less.js/packages/test-data/errors/eval/javascript-error: FAIL
SyntaxError: JavaScript evaluation error: 'TypeError: Cannot read property 'toJS' of undefined' in /home/runner/work/less.js/less.js/packages/test-data/errors/eval/javascript-error.less on line 2, column 10:¶
SyntaxError: JavaScript evaluation error: 'TypeError: Cannot read properties of undefined (reading 'toJS')' in /home/runner/work/less.js/less.js/packages/test-data/errors/eval/javascript-error.less on line 2, column 10:¶
1 .scope {
2     var: `this.foo.toJS`;
3 }

[iChenLei]

@MoonCoral Yes, it's not your issue.
@matthew-dean Hi, Matthew. What't your opinion about this CI failure case ?

[iChenLei]

@MoonCoral Please update your branch, upstream master branch solved the CI problem.

[MoonCoral]

Rebased on master

[iChenLei]

@MoonCoral CI has been fixed, please update your work, thanks !

[matthew-dean]

If all other tests pass, this seems good.