Cleanup unused Dockerfiles and build_all.yml workflow. (#18222)

Follow-up to https://github.com/iree-org/iree/pull/18144. Related to
https://github.com/iree-org/iree/issues/15332.

* `build_all.yml` was used as the first step in multiple other
workflows. New workflows are using `pkgci_build_packages.yml` directly
or nightly releases. Workflows could also use historical artifacts from
`pkgci_build_packages.yml` if they want to use versions different from
the nightly releases.
* `android.Dockerfile` was used for Android builds and benchmarks. New
workflows install the NDK on demand without needing a large Dockerfile.
* `nvidia.Dockerfile` and `nvidia-bleeding-edge.Dockerfile` were used
for CUDA/Vulkan benchmarks. New workflows rely on the drivers and
software packages that are already installed on runners. We could have
workflows install on demand or add new Dockerfiles as needed.