Relax API rate limits for self-hosted deployments (#2465)

- Introduced NoopApiRateLimiter to effectively disable API rate limiting for self-hosted mode.
- Updated ApiRateLimiter to delegate to NoopApiRateLimiter when running self-hosted.
- Increased Rack::Attack throttle limits significantly for self-hosted deployments.
- Added tests for NoopApiRateLimiter to ensure correct behavior.
- This allows self-hosted users to make more API requests without restriction, while keeping stricter limits for SaaS deployments.

app/services/noop_api_rate_limiter.rb

@@ -0,0 +1,39 @@
+class NoopApiRateLimiter
+  def initialize(api_key)
+    @api_key = api_key
+  end
+
+  def rate_limit_exceeded?
+    false
+  end
+
+  def increment_request_count!
+    # No operation
+  end
+
+  def current_count
+    0
+  end
+
+  def rate_limit
+    Float::INFINITY
+  end
+
+  def reset_time
+    0
+  end
+
+  def usage_info
+    {
+      current_count: 0,
+      rate_limit: Float::INFINITY,
+      remaining: Float::INFINITY,
+      reset_time: 0,
+      tier: :noop
+    }
+  end
+
+  def self.usage_for(api_key)
+    new(api_key).usage_info
+  end
+end