Slow to populate the Terminal > Integrated > Tabs: Default Icon dropdown

<!-- ⚠️⚠️ Do Not Delete This! bug_report_template ⚠️⚠️ --> Does this issue occur when all extensions are disabled?: Yes - VS Code Version: 1.70 Insiders - OS Version: Windows 11 Steps to Reproduce: 1. In the Settings editor, go to the Terminal > Integrated > Tabs: Default Icon setting. Icon default is "terminal". 2. Click the down pointing chevron to expand the dropdown. Because the list of available codicons is so large, it takes about 3 seconds for the dropdown to appear