Update composer.lock for format_strawberryfield citeproc-php requirement

[aksm]

What?

Following esmero/format_strawberryfield#227, the composer.lock needs to be updated to include the requirement.

[DiegoPino]

Solved via https://github.com/esmero/archipelago-deployment/commit/c340749f4895901d78b7afa9151bd55efd74b77f thanks @aksm