[BUGFIX] Flush configuration cache upon ``PackageStates`` update
This change makes sure that the configuration cache is flushed whenever
the ``PackageStates.php`` file is being updated.
Since I1f9d560303758c87b81a8b5578f1b80b76deb398 a compile time
configuration cache is built even in ``Development`` context.
When this cache is not flushed after creating a new package, this
leads to an fatal error::
Argument 1 passed to ActionController::injectSettings() must be
of the type array, null given
The reason is, that we currently initialize an empty setting for every
package in the ``ConfigurationManager``. If the cache is not rebuilt
upon creation of new Packages, this initialization is skipped and::
Releases: master, 3.0