ci: add apt-get update/upgrade - #307

…#307)

Follow-up to amule-project#295: the old `#ifdef __WXOSX__` right/bottom pads (14/9)
compensated for `AssignImageList`'s NSTableView render path — zero
native icon/text gap plus vertical-centre-of-the-full-bitmap, which
made a bare 16x16 icon sit flush against the label and drift toward
the row baseline. `SetSmallImages` uses a different wxOSX path that
already inserts native icon/text spacing, so the pads now render as
visible extra whitespace between icon and label. Drop them (and the
now-dead `img.Size()` pass) so wxOSX matches Windows/Linux layout.

Verified locally: rebuilt on macOS 15 ARM64 (wxOSX Cocoa 3.3.2), page
icons now sit at the natural offset the wx-native path picks. No
change on wxGTK or wxMSW paths (both pads were already 0 there).