bob-sepolia: force OP_NODE_OVERRIDE_JOVIAN; drop stale op/bob.by backup

bob-sepolia is past the Jovian hardfork (jovian_time=1772548201). Conduit's
downloaded rollup.json omits jovian_time, so op-node misparsed the 178-byte
Jovian L1-info deposit txs ("data is unexpected length: 178") and the node
stalled at genesis. Add OP_NODE_OVERRIDE_JOVIAN to all bob-sepolia variants.

Remove op/bob.by: an unused local genesis/rollup backup. Source of truth is
the genesis/rollup downloaded from the Conduit URLs in context.yml.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

op/reth/bob-sepolia-op-reth-archive-trace.yml

@@ -160,6 +160,7 @@ services:
       - OP_NODE_METRICS_ADDR=0.0.0.0
       - OP_NODE_METRICS_ENABLED=true
       - OP_NODE_METRICS_PORT=7300
+      - OP_NODE_OVERRIDE_JOVIAN=1772548201
       - OP_NODE_OVERRIDE_PECTRABLOBSCHEDULE=1742486400
       - OP_NODE_P2P_ADVERTISE_IP=${IP}
       - OP_NODE_P2P_LISTEN_IP=0.0.0.0

op/reth/bob-sepolia-op-reth-minimal-trace.yml

@@ -160,6 +160,7 @@ services:
       - OP_NODE_METRICS_ADDR=0.0.0.0
       - OP_NODE_METRICS_ENABLED=true
       - OP_NODE_METRICS_PORT=7300
+      - OP_NODE_OVERRIDE_JOVIAN=1772548201
       - OP_NODE_OVERRIDE_PECTRABLOBSCHEDULE=1742486400
       - OP_NODE_P2P_ADVERTISE_IP=${IP}
       - OP_NODE_P2P_LISTEN_IP=0.0.0.0

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

@@ -161,6 +161,7 @@ services:
       - OP_NODE_METRICS_ADDR=0.0.0.0
       - OP_NODE_METRICS_ENABLED=true
       - OP_NODE_METRICS_PORT=7300
+      - OP_NODE_OVERRIDE_JOVIAN=1772548201
       - OP_NODE_OVERRIDE_PECTRABLOBSCHEDULE=1742486400
       - OP_NODE_P2P_ADVERTISE_IP=${IP}
       - OP_NODE_P2P_LISTEN_IP=0.0.0.0