Update docker container image for unit test

[JSUYA]

https://github.com/flutter-tizen/embedder/blob/master/.github/workflows/build-docker.yml
The image used for the Docker container for the unit tests is very old.
The REPO_URL used no longer exists.

It needs to be updated to include libvulkan.so to resolve the issue below.
https://github.com/flutter-tizen/embedder/actions/runs/16957080552/job/48061829086?pr=110#step:7:14

[JSUYA]

The container's image has been updated.
https://github.com/flutter-tizen/engine/pkgs/container/tizen-headed-armv7l/497484101?tag=latest

However, this hasn't resolved the unit test failure issue.

[swift-kim]

Need help? This may work:

wget -q https://download.tizen.org/releases/milestone/TIZEN/Tizen/Tizen-Unified/latest/repos/standard/packages/armv7l/vulkan-loader-1.3.268-0.armv7l.rpm
rpm2cpio vulkan-loader-1.3.268-0.armv7l.rpm | cpio -idmv -D rootfs
# ... docker import ...

[JSUYA]

Need help? This may work:

wget -q https://download.tizen.org/releases/milestone/TIZEN/Tizen/Tizen-Unified/latest/repos/standard/packages/armv7l/vulkan-loader-1.3.268-0.armv7l.rpm
rpm2cpio vulkan-loader-1.3.268-0.armv7l.rpm | cpio -idmv -D rootfs

Thank you for your advice. I will add that code