Results from Upgrade Status scan: Instantiation of deprecated class Masterminds\HTML5\Parser\StringInputStream: since 2.4, to remove in 3.0. Use a string in the scanner instead.
on media_migration/src/Plugin/migrate/process/CKEditorLinkFileToLinkitFilter.php:104
and media_migration/src/Plugin/migrate/process/ImgTagToEmbedFilter.php:123
Carry out a scan of the module using Upgrade Status module.
Remove usage of StringInputStream in favour of direct string.
Provide issue fork.
Closed: works as designed
1.0
Documentation
This is a false positive, and is just used to support an older version of the library.
See https://github.com/Masterminds/html5-php/commit/321ed9626c091f1f4dcef822...