[Aikido] Fix security issue in concurrent-ruby via minor version upgrade from 1.3.6 to 1.3.7 in docs

[aikido-autofix]

Upgrade concurrent-ruby to fix critical synchronization vulnerabilities: improper lock release allowing concurrent writers, infinite loops with NaN values causing DoS, and write lock bypass after 32k read acquisitions.

✅ 3 CVEs resolved by this upgrade, including 1 critical 🚨 CVE

This PR will resolve the following CVEs:

Issue	Severity	Description
CVE-2026-54906	🚨 CRITICAL	[concurrent-ruby] A synchronization vulnerability allows any thread to release another thread's write lock, enabling concurrent write access violations. Additionally, releasing a read lock without holding one corrupts the lock state, causing subsequent read acquisitions to fail.
CVE-2026-54904	HIGH	[concurrent-ruby] AtomicReference#update enters an infinite busy loop when the stored value is Float::NAN due to NaN comparison semantics, causing CPU exhaustion or permanent hangs in affected services.
CVE-2026-54905	MEDIUM	[concurrent-ruby] ReentrantReadWriteLock incorrectly grants write locks after 32,768 reentrant read acquisitions due to integer overflow in lock state tracking, breaking mutual exclusion and allowing concurrent read/write access. This enables data corruption and race conditions.