Fix parsing crash for update in later phases

Author: bracevac

compiler/src/dotty/tools/dotc/parsing/Parsers.scala

@@ -3291,7 +3291,7 @@ object Parsers {
           case nme.infix => Mod.Infix()
           case nme.tracked => Mod.Tracked()
           case nme.erased if in.erasedEnabled => Mod.Erased()
-          case nme.update if Feature.ccEnabled => Mod.Update()
+          case nme.update => Mod.Update()
         }
     }
 

tests/neg-custom-args/captures/i23389-1.scala

@@ -0,0 +1,8 @@
+import language.experimental.captureChecking
+import caps.*
+
+trait Collection[+T] extends Mutable:
+  update def add(elem: T): Unit // error
+  update def remove(elem: T): Unit // error
+  def get(index: Int): Option[T]
+

tests/neg-custom-args/captures/i23389-2.scala

@@ -0,0 +1,8 @@
+import language.experimental.captureChecking
+import caps.*
+
+trait Collection[T] extends Mutable // <- note the forgotten :
+  update def add(elem: T): Unit // error // error
+  update def remove(elem: T): Unit // error // error
+  def get(index: Int): Option[T] // error // error
+