Update haxe, fix null safety issues (#127)

Author: kLabz

.haxerc

@@ -1,4 +1,4 @@
 {
-  "version": "15abdcc",
+  "version": "b537e99",
   "resolveLibs": "scoped"
 }

src/haxeLanguageServer/features/haxe/codeAction/diagnostics/AddTypeHintActions.hx

@@ -155,7 +155,7 @@ class AddTypeHintActions {
 				return action;
 			final range = if (isFunName) {
 				// add return type hint
-				final pOpen = defToken.access().firstOf(POpen).token ?? return action;
+				final pOpen = defToken.access().firstOf(POpen)?.token ?? return action;
 				final pos = pOpen.getPos();
 				document.rangeAt(pos.max, pos.max, Utf8);
 			} else {

src/haxeLanguageServer/features/haxe/codeAction/diagnostics/MissingArgumentsAction.hx

@@ -141,12 +141,12 @@ class MissingArgumentsAction {
 			case AnonymousStructure:
 				return "obj";
 			case ClassField:
-				return item.args!.field!.name ?? "arg";
+				return item.args?.field?.name ?? "arg";
 			case Expression:
 				if (item.type!.kind == TFun)
 					return "callback";
 			case _:
-				return item.args!.name ?? "arg";
+				return item.args?.name ?? "arg";
 		}
 		return genArgNameFromJsonType(item.type);
 	}