tests: Update block hashes and POI values for Foundry 1.3.1

The CI environment is now using Foundry 1.3.1, which generates different
block hashes than previous versions despite using the same deterministic
timestamp (1743944919). This updates the expected values in the grafting
integration test to match the new hashes.

Block hash changes:
- Block 1: 9f8d0597bbea45bf324877e27f97d72fabbaf0728f27c599ef48bc18f5c2f570
- Block 2: d694754323a237830532e8bcf0ab5dad7e7a68f1a258eaf6f568f1bdc8b80777
- Block 3: d8640638dd8a0c7843b9f93d1b9540e4ace1f7cbfcf2a91908f413e66d3edf33

POI value changes:
- Block 1: 0x28c9a9d5165027d635f4eb4ad72162a2f7a124e01fcd6da69f546379ee547711
- Block 2: 0xed70c4d7db44afc5190934889deaa800452fdb61e3eb78b9914708004c7b1bca
- Block 3: 0x585a9faa1762d66874be5c5cd9064388b95d54fd48ff3c122189a1ae7f016a85

🤖 Generated with [Claude Code](https://claude.ai/code)

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

Author: fubhy

tests/tests/integration_tests.rs

@@ -896,15 +896,15 @@ async fn test_subgraph_grafting(ctx: TestContext) -> anyhow::Result<()> {
     assert!(subgraph.healthy);
 
     let block_hashes: Vec<&str> = vec![
-        "384c705d4d1933ae8ba89026f016f09854057a267e1143e47bb7511d772a35d4",
-        "b90423eead33404dae0684169d35edd494b36802b721fb8de0bb8bc036c10480",
-        "2a6c4b65d659e0485371a93bc1ac0f0d7bc0f25a454b5f23a842335fea0638d5",
+        "9f8d0597bbea45bf324877e27f97d72fabbaf0728f27c599ef48bc18f5c2f570",
+        "d694754323a237830532e8bcf0ab5dad7e7a68f1a258eaf6f568f1bdc8b80777",
+        "d8640638dd8a0c7843b9f93d1b9540e4ace1f7cbfcf2a91908f413e66d3edf33",
     ];
 
     let pois: Vec<&str> = vec![
-        "0xde9e5650e22e61def6990d3fc4bd5915a4e8e0dd54af0b6830bf064aab16cc03",
-        "0x5d790dca3e37bd9976345d32d437b84ba5ea720a0b6ea26231a866e9f078bd52",
-        "0x719c04b78e01804c86f2bd809d20f481e146327af07227960e2242da365754ef",
+        "0x28c9a9d5165027d635f4eb4ad72162a2f7a124e01fcd6da69f546379ee547711",
+        "0xed70c4d7db44afc5190934889deaa800452fdb61e3eb78b9914708004c7b1bca",
+        "0x585a9faa1762d66874be5c5cd9064388b95d54fd48ff3c122189a1ae7f016a85",
     ];
 
     for i in 1..4 {