[ui] remove package_info_plus dependency

Benefits:
- Fewer dependencies (yay!)
- We now need to update the app version on new releases only in two
  places: `pubspec.yaml` and `lib/constants.dart`. I plan to create a
  release guide so we don't forget either when creating a new
  release[1].

[1]: Lacerte#285

lib/constants.dart

@@ -0,0 +1 @@
+const appVersion = '2.0.1';

lib/ui/screens/about_screen.dart

@@ -4,6 +4,7 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/.
  */
 
+import 'package:clima/constants.dart';
 import 'package:clima/ui/build_flavor.dart';
 import 'package:clima/ui/widgets/dialogs/credits_dialog.dart';
 import 'package:clima/ui/widgets/dialogs/help_and_feedback_dialog.dart';
@@ -12,7 +13,6 @@ import 'package:clima/ui/widgets/settings/settings_header.dart';
 import 'package:clima/ui/widgets/settings/settings_tile.dart';
 import 'package:flutter/material.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
-import 'package:package_info_plus/package_info_plus.dart';
 import 'package:url_launcher/url_launcher.dart';
 
 class AboutScreen extends StatelessWidget {
@@ -43,14 +43,14 @@ class AboutScreen extends StatelessWidget {
               ),
               SettingsTile(
                 title: 'Changelog',
-                subtitle: 'Version 2.0.1',
+                subtitle: 'Version $appVersion',
                 leading: Icon(
                   Icons.new_releases_outlined,
                   color: Theme.of(context).iconTheme.color,
                 ),
                 onTap: () => launchUrl(
                   Uri.parse(
-                    'https://github.com/lacerte/clima/releases/tag/v2.0.1',
+                    'https://github.com/lacerte/clima/releases/tag/v$appVersion',
                   ),
                 ),
               ),
@@ -75,13 +75,11 @@ class AboutScreen extends StatelessWidget {
                   Icons.source_outlined,
                   color: Theme.of(context).iconTheme.color,
                 ),
-                onTap: () async {
-                  final PackageInfo packageInfo =
-                      await PackageInfo.fromPlatform();
+                onTap: () {
                   showLicensePage(
                     context: context,
-                    applicationName: packageInfo.appName,
-                    applicationVersion: packageInfo.version,
+                    applicationName: 'Clima',
+                    applicationVersion: appVersion,
                   );
                 },
               ),

pubspec.lock

@@ -478,48 +478,6 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "2.1.0"
-  package_info_plus:
-    dependency: "direct main"
-    description:
-      name: package_info_plus
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.4.2"
-  package_info_plus_linux:
-    dependency: transitive
-    description:
-      name: package_info_plus_linux
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.0.5"
-  package_info_plus_macos:
-    dependency: transitive
-    description:
-      name: package_info_plus_macos
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.3.0"
-  package_info_plus_platform_interface:
-    dependency: transitive
-    description:
-      name: package_info_plus_platform_interface
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.0.2"
-  package_info_plus_web:
-    dependency: transitive
-    description:
-      name: package_info_plus_web
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.0.5"
-  package_info_plus_windows:
-    dependency: transitive
-    description:
-      name: package_info_plus_windows
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.0.5"
   path:
     dependency: transitive
     description:

pubspec.yaml

@@ -20,7 +20,6 @@ dependencies:
     git:
       url: https://github.com/CentaurusApps/material_floating_search_bar.git
       ref: 07b2980ad304dacaa5688e56483adcec36fb08ab
-  package_info_plus: 1.4.2
   riverpod: 1.0.3
   shared_preferences: 2.0.15
   font_awesome_flutter: 10.1.0