flutter pub upgrade (#926)

* flutter pub upgrade

* `desktop_photo_search`: Remove unneeded `unawaited`

Co-authored-by: John Ryan <ryjohn@google.com>

jsonexample/pubspec.lock

@@ -42,7 +42,7 @@ packages:
       name: build
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0"
+    version: "2.1.1"
   build_config:
     dependency: transitive
     description:
@@ -56,7 +56,7 @@ packages:
       name: build_daemon
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.0.0"
+    version: "3.0.1"
   build_resolvers:
     dependency: transitive
     description:
@@ -70,14 +70,14 @@ packages:
       name: build_runner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.2"
+    version: "2.1.4"
   build_runner_core:
     dependency: transitive
     description:
       name: build_runner_core
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "7.1.0"
+    version: "7.2.2"
   built_collection:
     dependency: "direct main"
     description:
@@ -126,7 +126,7 @@ packages:
       name: cli_util
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.3.3"
+    version: "0.3.4"
   clock:
     dependency: transitive
     description:
@@ -168,7 +168,7 @@ packages:
       name: dart_style
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0"
+    version: "2.1.1"
   fake_async:
     dependency: transitive
     description:
@@ -220,7 +220,7 @@ packages:
       name: glob
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.1"
+    version: "2.0.2"
   graphs:
     dependency: transitive
     description:
@@ -456,7 +456,7 @@ packages:
       name: watcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.0"
+    version: "1.0.1"
   web_socket_channel:
     dependency: transitive
     description:
@@ -472,4 +472,4 @@ packages:
     source: hosted
     version: "3.1.0"
 sdks:
-  dart: ">=2.12.0 <3.0.0"
+  dart: ">=2.14.0 <3.0.0"