misc: remove unneeded OPENSSL_NO_VENDOR

[branchv]

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• Have you ensured that your commits follow the commit style guide?
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• Have you built your formula locally with HOMEBREW_NO_INSTALL_FROM_API=1 brew install --build-from-source <formula>?
• Is your test running fine brew test <formula>?
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OPENSSL_NO_VENDOR was moved to superenv way back in Homebrew/brew@c3be703

[chenrui333]

• extend/ENV/super: set OPENSSL_NO_VENDOR brew#15613