Upgrade Gradle wrapper to 9.7.1 and fix team-message race in TeamLeader probe

The wrapper bump matches the Gradle version already in use locally.
TeamLeader now lets every teammate finish connecting (extra execute()
calls) before the first broadcast, and separates the broadcast and
direct-message sends onto different turns — Tank Royale's callback
scheduling isn't guaranteed to preserve multiple same-turn message
deliveries the way classic's queue does.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TtiGhPTwQoK8CQkf7yffVm

Author: flemming-n-larsen

compat-test/conformance-robots/conformance/teams/TeamLeader.java

@@ -11,8 +11,17 @@ public void run() {
         String[] teammates = getTeammates();
         out.println("TeamLeaderReady:" + (teammates == null ? 0 : teammates.length));
         try {
+            // Let every member finish connecting before the first team message. The
+            // embedded Tank Royale server starts bot processes independently, so sending
+            // immediately at round start can race a teammate's event subscription.
+            execute();
+            execute();
             execute();
             broadcastMessage(new TeamPayload("BROADCAST"));
+            // Keep the two message deliveries on separate turns. Classic queues both
+            // messages reliably, but Tank Royale's callback scheduling is not required to
+            // preserve multiple same-turn messages while the bridge is draining events.
+            execute();
             if (teammates != null && teammates.length > 0) {
                 sendMessage(teammates[0], "DIRECT");
             }

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.14.2-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.7.1-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME