Bump op-node version from v1.19.6 to v1.19.7

Update op-node version in op-family defaults and zircuit chain overrides
to match the new release. This affects all OP-stack chains using the
standard op-node image that inherit from the family default or have
explicit overrides that should be kept in step.

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

op/reth/unichain-sepolia-op-reth-pruned-trace.yml

@@ -112,7 +112,7 @@ services:
     shm_size: 2gb
 
   unichain-sepolia-op-reth-pruned-node:
-    image: ${UNICHAIN_NODE_IMAGE:-us-docker.pkg.dev/oplabs-tools-artifacts/images/op-node}:${UNICHAIN_SEPOLIA_NODE_VERSION:-v1.19.6}
+    image: ${UNICHAIN_NODE_IMAGE:-us-docker.pkg.dev/oplabs-tools-artifacts/images/op-node}:${UNICHAIN_SEPOLIA_NODE_VERSION:-v1.19.7}
     ports:
       - 19152:19152
       - 19152:19152/udp