benchmark: fix broken fs.cpSync benchmark

benchmark: fix broken fs.cpSync benchmark · nodejs/node@8bc0452

Original file line number	Diff line number	Diff line change
`@@ -8,7 +8,10 @@ const tmpdir = require('../../test/common/tmpdir');`
`8`	`8`	`const bench = common.createBenchmark(main, {`
`9`	`9`	`n: [1, 100, 10_000],`
`10`	`10`	`dereference: ['true', 'false'],`
`11`		`-force: ['true', 'false'],`
	`11`	+// When `force` is `true` the `cpSync` function is called twice the second
	`12`	+// time however an `ERR_FS_CP_EINVAL` is thrown, so skip `true` for the time being
	`13`	+// TODO: allow `force` to also be `true` once https://github.com/nodejs/node/issues/58468 is addressed
	`14`	`+force: ['false'],`
`12`	`15`	`});`
`13`	`16`
`14`	`17`	`function prepareTestDirectory() {`