OpenSSL usage deprecation warnings from Rubocop

[tas50]

Rubocop has a new cop that detects an upcoming deprecation to the OpenSSL gem that's built into Ruby.

The openssl introducing the deprecation:
ruby/openssl#366

The new rubocop rule currently only in master:
rubocop/rubocop#7950

/Users/tsmith/dev/work/inspec/lib/inspec/fetcher/git.rb:102:7: W: Lint/DeprecatedOpenSSLConstant: Use OpenSSL::Digest.hexdigest('SHA256', resolved_ref + @relative_path) instead of OpenSSL::Digest::SHA256.hexdigest(resolved_ref + @relative_path).
      OpenSSL::Digest::SHA256.hexdigest(resolved_ref + @relative_path)
      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
/Users/tsmith/dev/work/inspec/lib/inspec/fetcher/local.rb:107:25: W: Lint/DeprecatedOpenSSLConstant: Use OpenSSL::Digest.digest('SHA256', File.read(target)) instead of OpenSSL::Digest::SHA256.digest(File.read(target)).
      @archive_shasum = OpenSSL::Digest::SHA256.digest(File.read(target)).unpack("H*")[0]
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
/Users/tsmith/dev/work/inspec/lib/inspec/fetcher/url.rb:130:27: W: Lint/DeprecatedOpenSSLConstant: Use OpenSSL::Digest.digest('SHA256', File.read(@archive_path || temp_archive_path)) instead of OpenSSL::Digest::SHA256.digest(File.read(@archive_path || temp_archive_path)).
      @archive_shasum ||= OpenSSL::Digest::SHA256.digest(File.read(@archive_path || temp_archive_path)).unpack("H*")[0]
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
/Users/tsmith/dev/work/inspec/lib/inspec/profile.rb:562:13: W: Lint/DeprecatedOpenSSLConstant: Use OpenSSL::Digest.new('SHA256') instead of OpenSSL::Digest::SHA256.new.
      res = OpenSSL::Digest::SHA256.new
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^

[Schwad]

@tas50 running pipeline on these changes in #5035 to see if we run green. Thanks for providing the examples and background! 🙏