bump(main/libpixman): 0.43.4

[twaik]

Requires some testing with two or more reverse dependencies.

  xwayland
  xorg-server-xvfb
  xorg-server-xephyr
  xorg-server
  wlroots
  wayvnc
  tigervnc-viewer
  tigervnc
  thunderbird
  qemu-system-x86-64
  qemu-system-riscv64
  qemu-system-riscv32
  qemu-system-ppc64
  qemu-system-ppc
  qemu-system-m68k
  qemu-system-i386
  qemu-system-arm
  qemu-system-aarch64
  picom
  libneatvnc
  libfcft
  gtk2-engines-murrine
  foot
  firefox
  texlive-bin
  qemu-utils
  qemu-user-x86-64
  qemu-user-riscv64
  qemu-user-riscv32
  qemu-user-ppc64
  qemu-user-ppc
  qemu-user-m68k
  qemu-user-i386
  qemu-user-arm
  qemu-user-aarch64
  qemu-system-x86-64-headless
  qemu-system-riscv64-headless
  qemu-system-riscv32-headless
  qemu-system-ppc64-headless
  qemu-system-ppc-headless
  qemu-system-m68k-headless
  qemu-system-i386-headless
  qemu-system-arm-headless
  qemu-system-aarch64-headless
  qemu-common
  libspice-server
  libcairo
  libfcft

[TomJo2000]

Closed in #20310, please review if any changed from this PR still need to be applied to libpixman's build script.