cve-check: add lockfile to task

this should prevent running into the very rare error
sqlite3.OperationalError: attempt to write a readonly database

As highlighted by https://www.sqlite.org/faq.html#q5


it is likely that the adapter won't allow use multiple exec calls
at the same time.

So it's best to prevent multiple accesses at a time, by reusing
the already in place CVE_CHECK_DB_FILE_LOCK

YOCTO #14110

Signed-off-by: Konrad Weihmann <kweihmann@outlook.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>