Fix lint warnings

@@ -76,12 +76,12 @@ class Calendar extends StatelessWidget {
     PdfColor color = PdfColors.grey300;
     PdfColor color = PdfColors.grey300;
 
 
     if (currentDay) {
     if (currentDay) {
-      style = TextStyle(color: PdfColors.red);
+      style = const TextStyle(color: PdfColors.red);
       color = PdfColors.lightBlue50;
       color = PdfColors.lightBlue50;
     }
     }
 
 
     if (!currentMonth) {
     if (!currentMonth) {
-      style = TextStyle(color: PdfColors.grey);
+      style = const TextStyle(color: PdfColors.grey);
       color = PdfColors.grey100;
       color = PdfColors.grey100;
     }
     }
 
 

@@ -37,7 +37,7 @@ Uint8List buildPdf() {
         child: FittedBox(
         child: FittedBox(
           child: Text(
           child: Text(
             'Hello!',
             'Hello!',
-            style: TextStyle(color: PdfColors.blueGrey),
+            style: const TextStyle(color: PdfColors.blueGrey),
           ),
           ),
         ),
         ),
       );
       );