emacs: build pgtk variant with full image support
emacs: build pgtk variant with full image support

Emacs built with pgtk ("pure gtk") isn't X, so `withX` isn't true.
This commit extends the test conditions for format libraries inclusion
to withX || withPgtk, so Pgtk Emacs gets image format support
libraries as well.

Co-authored-by: Atemu <07f51b3c29c0b614f23d2581629f478d827bc80b@gmail.com>

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