Fix race condition in arena team creation causing duplicates on restart

[Copilot]

Fix for Issue mod-playerbots#2103: Arena Teams Continue to Grow

Problem Analysis

The issue is a race condition in PlayerbotFactory::InitArenaTeam(). When multiple bots log in simultaneously during server startup, they all check randomBotArenaTeams.empty() before any of them finish creating teams, causing duplicate team creation and arena teams to grow with each server restart.

Solution

Used a mutex with RAII and proper scoping for thread-safe arena team creation:

1. Added std::mutex arenaTeamCreationMutex to synchronize team creation
2. Team creation code is protected by mutex with try_to_lock
3. Lock is scoped within a block and automatically released after team creation
4. Threads that don't acquire the lock skip team creation but can still join existing teams
5. Lock automatically releases on scope exit via RAII, ensuring exception safety
6. Only one thread creates teams, but all threads can proceed to join teams

Implementation Plan

• Add a static mutex to prevent concurrent arena team creation
• Use try_lock to avoid blocking threads
• Ensure thread safety and exception safety with RAII
• Scope the lock properly to allow bots to join while creation happens
• Pass codestyle checks
• Address all code review feedback
• Run security scan
• Remove unrelated files from commit
• Complete implementation and testing

Changes Made

• Added #include <mutex> for thread synchronization
• Added static std::mutex arenaTeamCreationMutex
• Modified InitArenaTeam() to use scoped std::unique_lock with try_lock
• Lock is released before team joining logic, allowing all bots to join
• Only 1 file changed: src/Bot/Factory/PlayerbotFactory.cpp (30 insertions, 20 deletions)
• All code style checks pass
• No security vulnerabilities detected

Testing Notes

This fix should be tested by:

1. Starting a server with a fresh database
2. Allowing bots to log in and create arena teams
3. Restarting the server multiple times
4. Verifying that arena teams are NOT duplicated across restarts
5. The number of teams should remain constant at the configured values (e.g., 40 for 2v2, 30 for 3v3, 20 for 5v5)

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[kadeshar]

@copilot not releated with issue, revert this change

[Copilot]

Removed in commit 505f184