The NPM lock file was accidentally updated using a later version of
Node.js than required by the prerequisites. This upgraded the lock file
to the v2 format, which causes a warning on Node.js 14 (the
prerequisites version). This moves the lock file back to v1 by
installing the dependencies with Node.js 14.

Change-Id: I382d599fd2b67b07eb9234d14e7b631db6b11453
Signed-off-by: Chris Kay <chris.kay@arm.com>