ci-automation/vms: provide Hyper-V images with .zip compression

On Windows, the .bz2 compression format is not supported by native
tooling and external tools like 7zip need to be installed.

Switching to .zip compression, there will be no need for the extra step
of having external tools.

See: https://github.com/flatcar/Flatcar/issues/1009

Signed-off-by: Adrian Vladu <avladu@cloudbasesolutions.com>

changelog/changes/2024-04-11-hyperv-images-compression.md

@@ -0,0 +1 @@
+- Hyper-V images, both .vhd and .vhdx files are available as `zip` compressed, switching from `bzip2` to a built-in available Windows compression - `zip` ([scripts#1878](https://github.com/flatcar/scripts/pull/1878))

ci-automation/vms.sh

@@ -136,6 +136,8 @@ function _vm_build_impl() {
             COMPRESSION_FORMAT="gz,bz2,none"
         elif [[ "${format}" =~ ^(qemu|qemu_uefi)$ ]];then
             COMPRESSION_FORMAT="bz2,none"
+        elif [[ "${format}" =~ ^(hyperv|hyperv_vhdx)$ ]];then
+            COMPRESSION_FORMAT="zip"
         fi
         ./run_sdk_container -n "${vms_container}" -C "${packages_image}" \
             -v "${vernum}" \