Fix a bug in my last PR

[zijchen]

I originally had this line in there, but I changed it to the one in #26049 thinking it's more readable, but they're not the same as now this becomes undefined in the callback. Apparently in JS, passing function directly as argument binds it to a specific object instance, but using "lambda" functions doesn't. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions

[coveralls]

Pull Request Test Coverage Report for Build 11808342124

Details

• 0 of 1 (0.0%) changed or added relevant line in 1 file are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.003%) to 41.715%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
extensions/sql-database-projects/src/controllers/projectController.ts	0	1	0.0%

Files with Coverage Reduction	New Missed Lines	%
extensions/notebook/src/book/bookTreeView.ts	1	36.91%

Totals
Change from base Build 11807843306:	-0.003%
Covered Lines:	30722
Relevant Lines:	68916

---

💛 - Coveralls