Support new `runtimeExecutable: "mocha"` in launch template

[andreamah]

When testing #1984, I found that the Add Configuration in launch.json still adds mocha using "program": "${workspaceFolder}/node_modules/mocha/bin/_mocha",

1. Open launch.json.
2. Add Configuration
3. Node.js: Mocha Tests
4. See "program": "${workspaceFolder}/node_modules/mocha/bin/_mocha", instead of the new runtimeExecutable: "mocha" 🐛