Update specs to run with IPv6 support disabled

[Blacksmoke16]

Resolves #15033

On my system I get the following pending specs, will compare with what CI has:

Pending:
  HTTP::WebSocket using IPv6
  Math Functions for computing quotient and remainder
  Number #round edge cases
  HTTP::Client sends the host header ipv6 with brackets
  String #reverse converts invalid code units to replacement char
  UDPSocket using IPv6
  UDPSocket #connect with a IPv6 address
  Path #expand converts a pathname to an absolute pathname, using a complete path assert
  Socket #bind using IPv6
  URI .parse unescaped @ in user/password should not confuse host
  TCPSocket #connect fails to connect IPv6 to IPv4 server
  TCPSocket #connect using IPv6
  Regex #matches_at_byte_index? negative
  Regex #match_at_byte_index negative
  Regex #match with pos negative
  OpenSSL::X509::Certificate #digest
  System hostname returns current hostname
  OpenSSL::SSL::Context ciphers uses intermediate default ciphers
  String#each_grapheme GB9c
  String#each_grapheme GB9c
  String#each_grapheme GB9c
  String#each_grapheme GB9c
  String#each_grapheme GB9c
  String#each_grapheme GB9c
  String#each_grapheme GB9c
  Spec matchers pending block is not compiled pending has block with valid syntax, but invalid semantics
  TCPServer settings
  TCPServer .new using IPv6