Remove deprecated Squiz.WhiteSpace.LanguageConstructSpacing sniff

[gsherwood]

Squiz.WhiteSpace.LanguageConstructSpacing has been deprecated in favour of Generic.WhiteSpace.LanguageConstructSpacing since 3.3.0 and should be removed in version 4.

[gsherwood]

The sniff has been removed + the muting of the error has been removed from the Squiz standard