On Windows, `phase_write_executable` does not use `java_bin` to find the relevant java binary

[wiwa]

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One issue is that this means Windows will not respect runtime_jdk. Another issue is that we have different code paths for finding the java binary.

https://github.com/bazelbuild/rules_scala/blob/cd556ccfc253bfd70659631079e39be412b5402d/scala/private/phases/phase_write_executable.bzl#L83