Propel

psalm cleanups (these methods can return null)

misc psalm related cleanups

switch to psalm.phar, allow newer psalm versions, add more psalm suppressions

(psalm) $value is already is_object(), so it cannot now be is_array() too (dead code)

clean up some PHP8.4 warnings - "implicity marking parameter ... as nullable is deprecated, the explict nullable type must be used instead ...", probably breaks code on older PHP variants where ?Object is not supported.