[Train] 1.46.0-wmf.13 status: blocked on T415619 - Creation of dynamic property MediaWiki\Language\Dependency\FileDependency::$filename is deprecated

This week's 1.46.0-wmf.13 version of MediaWiki is blocked[0] on testwikis.

We can't proceed until the following issue is resolved:

* T415619: Creation of dynamic property 
MediaWiki\Language\Dependency\FileDependency::$filename is deprecated 
{"exception":"[object] (ErrorException(code: 0)
- https://phabricator.wikimedia.org/T415619

As a deprecation warning, this would normally only block _next_ week's 
train, but it does appear to be some risk of creating an unacceptably 
high volume of logspam.

Once this issue is resolved, the train can proceed to group0.

Thank you for any help!

-- Your perpetually rumpled train crew

[0]. https://phabricator.wikimedia.org/T413804