Fail on `java_binary` in `deploy_env` of `java_export` (#777)
Fail on `java_binary` in `deploy_env` of `java_export` (#777)

`java_export` silently ignores `java_binary` targets in `deploy_env`
since their `JavaInfo` has an empty runtime classpath. Since this is
the direct opposite of how the attribute of the same name on
`java_binary` works, which only accepts `java_binary` targets, this is
quite error-prone and warrants a strong warning/failure.
bazelbuild/rules_jvm_external,bazelbuild/rules_jvm_external,bazelbuild/rules_jvm_external