test: improve coverage of lib/os.js

PR-URL: #38653
Refs: https://coverage.nodejs.org/coverage-52e4fb5b23157222/lib/os.js.html#L96
Reviewed-By: Darshan Sen <[email protected]>
Reviewed-By: Antoine du Hamel <[email protected]>
Reviewed-By: Anna Henningsen <[email protected]>
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Rich Trott <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Luigi Pinca <[email protected]>
Reviewed-By: Michael Dawson <[email protected]>

Author: pd4d10

test/parallel/test-os.js

@@ -247,6 +247,7 @@ assert.strictEqual(`${os.endianness}`, os.endianness());
 assert.strictEqual(`${os.tmpdir}`, os.tmpdir());
 assert.strictEqual(`${os.arch}`, os.arch());
 assert.strictEqual(`${os.platform}`, os.platform());
+assert.strictEqual(`${os.version}`, os.version());
 
 assert.strictEqual(+os.totalmem, os.totalmem());