chore: add ignores for backward compatibility

Author: incendial

lib/src/analyzers/unnecessary_nullable_analyzer/unnecessary_nullable_analyzer.dart

@@ -273,7 +273,8 @@ class UnnecessaryNullableAnalyzer {
   ) {
     final offset = element.codeOffset!;
     final lineInfo = unit.lineInfo;
-    final offsetLocation = lineInfo.getLocation(offset);
+    // ignore: unnecessary_non_null_assertion
+    final offsetLocation = lineInfo!.getLocation(offset);
 
     final sourceUrl = element.source!.uri;
 

lib/src/analyzers/unused_code_analyzer/unused_code_analyzer.dart

@@ -218,7 +218,8 @@ class UnusedCodeAnalyzer {
   ) {
     final offset = element.codeOffset!;
     final lineInfo = unit.lineInfo;
-    final offsetLocation = lineInfo.getLocation(offset);
+    // ignore: unnecessary_non_null_assertion
+    final offsetLocation = lineInfo!.getLocation(offset);
 
     final sourceUrl = element.source!.uri;
 

lib/src/analyzers/unused_l10n_analyzer/unused_l10n_analyzer.dart

@@ -233,7 +233,8 @@ class UnusedL10nAnalyzer {
   ) {
     final offset = element.codeOffset!;
     final lineInfo = unit.lineInfo;
-    final offsetLocation = lineInfo.getLocation(offset);
+    // ignore: unnecessary_non_null_assertion
+    final offsetLocation = lineInfo!.getLocation(offset);
 
     final sourceUrl = element.source!.uri;