Add a new line in the end of `lhcbproject.yml`

This is suggested by @rmatev in rmatev/lb-stack-setup!63 (comment 5984368)

It makes DaVinci more consistent with other LHCb software. Moreover, some legacy configuration tools may be broken by the absence of this new line, like the old lb-stack-setup.

added DPA-WP3 label

requested review from @pkoppenb

assigned to @jzhuo

approved this merge request

/ci-test

added ci-test-triggered label

• [2022-09-09 13:27] Validation started with lhcb-master-mr#5612

resolved all threads

merged

mentioned in commit c8c83414