nfpm_package produces symlinks in the rpm instead of packaging the file.

[leungster]

When we specify contents using bazel references, the resulting rpm has the symlink instead of the actual file.

contents:
  - src: "{{ index .Dependencies `@//cmd/rpm:binary}}"
    dst: "/bin/binary"

Starting with nfpm v2.13.0, symlinks are preserved instead of being evaluated. See PR goreleaser/nfpm#453

When nfpm_package is used, the bazel-out paths are symlinks back to the execroot. Since those links aren't evaluated, nfpm copies the symlinks as is.

I think the change is to evaluate the symlink here so that the bazel file output is directly referenced by nfpm.