Resolve issue with concurrent list modification during cache save

lib/consts.dart

@@ -9,7 +9,7 @@ class TTConsts {
   static get SESSION_SERVER =>
       "https://api.zontreck.com/timetrack/$UPDATE_CHANNEL/timetrack.php";
 
-  static const VERSION = "1.0.0-beta.20";
+  static const VERSION = "1.0.0-beta.21";
 
   static bool UPDATE_AVAILABLE = false;
   static UpdateChannel UPDATE_CHANNEL = UpdateChannel.beta;

lib/data.dart

@@ -392,13 +392,19 @@ class SessionData {
     }
 
     ListTag posX = ListTag();
-    for (var pos in positions) {
+    int len = positions.length;
+    int i = 0;
+    for (i = 0; i < len; i++) {
+      var pos = positions[i];
       posX.add(await pos.toNBT());
     }
     ct.put("pos", posX);
 
     ListTag myTrips = ListTag();
-    for (var trip in Trips) {
+    len = Trips.length;
+    i = 0;
+    for (i = 0; i < len; i++) {
+      var trip = Trips[i];
       myTrips.add(await trip.toNBT());
     }
     ct.put("trips", myTrips);

pubspec.yaml

@@ -16,7 +16,7 @@ publish_to: "none" # Remove this line if you wish to publish to pub.dev
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 # In Windows, build-name is used as the major, minor, and patch parts
 # of the product and file versions while build-number is used as the build suffix.
-version: 1.0.0-beta.20
+version: 1.0.0-beta.21
 
 environment:
   sdk: ^3.7.2