fix: font family warning (#5329)

frontend/appflowy_flutter/lib/shared/google_fonts_extension.dart

@@ -1,7 +1,14 @@
+import 'package:appflowy/workspace/application/settings/appearance/base_appearance.dart';
 import 'package:appflowy_backend/log.dart';
 import 'package:flutter/material.dart';
 import 'package:google_fonts/google_fonts.dart';
 
+const _defaultFontFamilies = [
+  defaultFontFamily,
+  builtInCodeFontFamily,
+  fallbackFontFamily,
+];
+
 // if the font family is not available, google fonts packages will throw an exception
 // this method will return the system font family if the font family is not available
 TextStyle getGoogleFontSafely(
@@ -12,19 +19,31 @@ TextStyle getGoogleFontSafely(
   double? letterSpacing,
   double? lineHeight,
 }) {
-  try {
-    return GoogleFonts.getFont(
-      fontFamily,
+  // if the font family is the built-in font family, we can use it directly
+  if (_defaultFontFamilies.contains(fontFamily)) {
+    return TextStyle(
+      fontFamily: fontFamily.isEmpty ? null : fontFamily,
       fontWeight: fontWeight,
       fontSize: fontSize,
       color: fontColor,
       letterSpacing: letterSpacing,
       height: lineHeight,
     );
-  } catch (e) {
-    Log.error(
-      'Font family $fontFamily is not available, using default font family instead',
-    );
+  } else {
+    try {
+      return GoogleFonts.getFont(
+        fontFamily,
+        fontWeight: fontWeight,
+        fontSize: fontSize,
+        color: fontColor,
+        letterSpacing: letterSpacing,
+        height: lineHeight,
+      );
+    } catch (e) {
+      Log.error(
+        'Font family $fontFamily is not available, using default font family instead',
+      );
+    }
   }
 
   return TextStyle(