Update from qemu 4.2.0 to qemu 5.0.0 for emulation-based CI jobs.

.github/workflows/main.yml

@@ -309,8 +309,8 @@ jobs:
         # way faster at arm emulation than the current version github actions'
         # ubuntu image uses. Disable as much as we can to get it to build
         # quickly.
-        curl https://download.qemu.org/qemu-4.2.0.tar.xz | tar xJf -
-        cd qemu-4.2.0
+        curl https://download.qemu.org/qemu-5.0.0.tar.xz | tar xJf -
+        cd qemu-5.0.0
         ./configure --target-list=${{ matrix.qemu_target }} --prefix=$HOME/qemu --disable-tools --disable-slirp --disable-fdt --disable-capstone --disable-docs
         make -j$(nproc) install