grammar: some cleanup

grammar.js

@@ -86,12 +86,10 @@ module.exports = grammar({
       seq(
         $._connection_path,
         repeat1(seq($.arrow, $._connection_path)),
-        optional(
         seq(
           optional(seq($._colon, optional($.label))),
           optional(seq(alias($._connection_block, $.block)))
         )
-        )
       ),
 
     _connection_path: ($) =>

src/grammar.json

@@ -88,9 +88,6 @@
             ]
           }
         },
-        {
-          "type": "CHOICE",
-          "members": [
         {
           "type": "SEQ",
           "members": [
@@ -146,11 +143,6 @@
               ]
             }
           ]
-            },
-            {
-              "type": "BLANK"
-            }
-          ]
         }
       ]
     },