deps: run memory hungry V8 test in exclusive mode

es6/typedarray-construct-offset-not-smi allocates a 2G block of memory
and if there  are multiple variants running at the same time this can
lead to crashes, OOM kills or the OS failing to allocate memory.
This patch limits us to running a single variant of the test.

Refs: https://github.com/nodejs/node/pull/6678

PR-URL: https://github.com/nodejs/node/pull/13263


Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>
Reviewed-By: Myles Borins <myles.borins@gmail.com>