cask/cask_loader: discard invalid macOS versions earlier

Author: cho-m

Library/Homebrew/cask/cask_loader.rb

@@ -412,15 +412,16 @@ def load(config:)
 
               dep_type = dep_value.keys.first
               if dep_type == :==
-                version_symbols = dep_value[dep_type].map do |version|
-                  MacOSVersion::SYMBOLS.key(version) || version
+                version_symbols = dep_value[dep_type].filter_map do |version|
+                  MacOSVersion::SYMBOLS.key(version)
                 end
-                next [dep_key, version_symbols]
+                next [dep_key, version_symbols.presence]
               end
 
               version_symbol = dep_value[dep_type].first
-              version_symbol = MacOSVersion::SYMBOLS.key(version_symbol) || version_symbol
-              [dep_key, "#{dep_type} :#{version_symbol}"]
+              version_symbol = MacOSVersion::SYMBOLS.key(version_symbol)
+              version_dep = "#{dep_type} :#{version_symbol}" if version_symbol
+              [dep_key, version_dep]
             end.compact
             begin
               depends_on(**dep_hash)