add custom on-chain-metrics target for both local and Dockerized version

Author: skudasov

framework/observability/compose/conf/prometheus.yml

@@ -2,6 +2,11 @@ global:
   scrape_interval: 10s
 
 scrape_configs:
+  - job_name: 'on-chain-metrics'
+    metrics_path: /on-chain-metrics
+    scrape_interval: 10s
+    static_configs:
+      - targets: [ 'host.docker.internal:9112', 'on-chain-metrics:9112']
   - job_name: 'otel-collector'
     scrape_interval: 10s
     static_configs: