[static] Store should write filehandles using :raw

[preaction]

When copying images using filehandles, we get a lot of warnings:

utf8 "\x8A" does not map to Unicode at lib/Statocles/Store.pm line 258, <$fh> line 55.
utf8 "\xB9" does not map to Unicode at lib/Statocles/Store.pm line 258, <$fh> line 55.
utf8 "\xCB" does not map to Unicode at lib/Statocles/Store.pm line 258, <$fh> line 55.

This is because we're treating filehandles as UTF-8, instead of raw.