test: validate fs.rename() when NODE_TEST_DIR on separate mount

When testing fs.rename() of an non-existent file, use a destination path
which is in the same directory. Otherwise we might trigger an `EXDEV`
error if NODE_TEST_DIR is a separate device than the current working
directory.

Fixes: https://github.com/nodejs/node/issues/21669

PR-URL: https://github.com/nodejs/node/pull/24707


Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>