Migrate from legacy com.google.gwt to org.gwtproject.

org.gwtproject starts being available at the 2.10.0 release, so upgrade to that where necessary.

See #1342 (comment)

RELNOTES=n/a
PiperOrigin-RevId: 457020479

Author: cpovirk

value/src/it/functional/pom.xml

@@ -60,7 +60,7 @@
       <scope>provided</scope>
     </dependency>
     <dependency>
-      <groupId>com.google.gwt</groupId>
+      <groupId>org.gwtproject</groupId>
       <artifactId>gwt-user</artifactId>
       <version>2.10.0</version>
     </dependency>

value/src/it/gwtserializer/pom.xml

@@ -34,9 +34,9 @@
   <dependencyManagement>
     <dependencies>
       <dependency>
-        <groupId>com.google.gwt</groupId>
+        <groupId>org.gwtproject</groupId>
         <artifactId>gwt</artifactId>
-        <version>2.9.0</version>
+        <version>2.10.0</version>
         <type>pom</type>
         <scope>import</scope>
       </dependency>
@@ -55,12 +55,12 @@
       <optional>true</optional>
     </dependency>
     <dependency>
-      <groupId>com.google.gwt</groupId>
+      <groupId>org.gwtproject</groupId>
       <artifactId>gwt-user</artifactId>
       <scope>test</scope>
     </dependency>
     <dependency>
-      <groupId>com.google.gwt</groupId>
+      <groupId>org.gwtproject</groupId>
       <artifactId>gwt-dev</artifactId>
       <scope>test</scope>
     </dependency>