Allow unused catch error variables

We use try catch blocks to handle rejected promises in
async await functions. Eslint forces us to have the error
variable but the typescript linter throws an error that
they're unused.

.eslintrc.js

@@ -23,7 +23,15 @@ module.exports = {
 
 		// problematic in TypeScript / ES6
 		'no-unused-vars': 'off',
-		'@typescript-eslint/no-unused-vars': 'error',
+		'@typescript-eslint/no-unused-vars': [ 'error', {
+			'args': 'after-used',
+			'argsIgnorePattern': '^_',
+			'caughtErrors': 'none',
+			'caughtErrorsIgnorePattern': '^_',
+			'destructuredArrayIgnorePattern': '^_',
+			'varsIgnorePattern': '^_',
+			'ignoreRestSiblings': true,
+		} ],
 		'one-var': 'off',
 		'no-undef': 'off',
 		// See https://stackoverflow.com/a/65768375/130121