curl_spec: remove no-op Marshal use

[woodruffw]

These seemingly do nothing.

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[woodruffw]

Closing; this Marshal round-trip is unfortunately load-bearing as an easy way to perform a deep clone.

[Bo98]

Would these work here? https://github.com/Homebrew/brew/blob/master/Library/Homebrew/extend/object/deep_dup.rb

[woodruffw]

Would these work here? master/Library/Homebrew/extend/object/deep_dup.rb

Ah, I was looking for this exact helper. Yes, that's exactly what it needs. Reopening.

[MikeMcQuaid]

Nice, thanks @woodruffw!

[MikeMcQuaid]

(confirmed ready for review because I was sitting next to @woodruffw!)