fixed deprecated warnings

refilc_mobile_ui/lib/common/widgets/absence/absence_display.dart

@@ -15,7 +15,7 @@ class AbsenceDisplay extends StatelessWidget {
       padding: const EdgeInsets.only(top: 5.0),
       // padding: const EdgeInsets.symmetric(vertical: 4.0, horizontal: 6.0),
       // decoration: BoxDecoration(
-      //   color: Theme.of(context).scaffoldBackgroundColor.withOpacity(.2),
+      //   color: Theme.of(context).scaffoldBackgroundColor.withValues(alpha: .2),
       //   borderRadius: BorderRadius.circular(12.0),
       // ),
       child: Row(children: [

refilc_mobile_ui/lib/common/widgets/absence/absence_subject_tile.dart

@@ -81,7 +81,7 @@ class AbsenceSubjectTile extends StatelessWidget {
                         // fontFamily: "monospace",
                         color:
                             getColorByPercentage(percentage, context: context)
-                                .withOpacity(0.8),
+                                .withValues(alpha: 0.8),
                         fontSize: 16.0,
                         fontWeight: FontWeight.w500,
                       ),
@@ -109,5 +109,5 @@ Color getColorByPercentage(double percentage, {required BuildContext context}) {
     color = AppColors.of(context).yellow;
   }
 
-  return color.withOpacity(.8);
+  return color.withValues(alpha: .8);
 }

refilc_mobile_ui/lib/common/widgets/absence/absence_tile.dart

@@ -57,7 +57,7 @@ class AbsenceTile extends StatelessWidget {
               width: 39,
               decoration: BoxDecoration(
                 shape: BoxShape.circle,
-                color: !group ? color.withOpacity(.25) : null,
+                color: !group ? color.withValues(alpha: .25) : null,
               ),
               child: Center(
                   child: Icon(justificationIcon(absence.state), color: color)),

refilc_mobile_ui/lib/common/widgets/absence/absence_view.dart

@@ -51,7 +51,7 @@ class AbsenceView extends StatelessWidget {
               height: 44.0,
               decoration: BoxDecoration(
                 shape: BoxShape.circle,
-                color: color.withOpacity(.25),
+                color: color.withValues(alpha: .25),
               ),
               child: Center(
                 child: Icon(