graphics/poppler: update to 21.12

Release 21.12.0:
    core:
         * Add API to add images
         * CairoOutputDev: Fix de-duping of Flate images
         * Fix crash on broken files when using non-default ENABLE_ZLIB_UNCOMPRESS. Issue #393
         * Minor code improvements

    glib:
         * Add API for validation of signatures
         * Add API to read/save to file descriptor

    utils:
         * pdftohtml: Reduce sensitivity of duplicate detection. Issue #1117

    build system:
         * Increase C++ standard to 17

Exp-run by:	antoine
PR:		260344