Bump @graphprotocol/graph-ts from 0.30.0 to 0.31.0 (#730)

Bumps @graphprotocol/graph-ts from 0.30.0 to 0.31.0.

---
updated-dependencies:
- dependency-name: "@graphprotocol/graph-ts"
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

package.json

@@ -49,7 +49,7 @@
   },
   "devDependencies": {
     "@graphprotocol/graph-cli": "^0.56.0",
-    "@graphprotocol/graph-ts": "^0.30.0",
+    "@graphprotocol/graph-ts": "^0.31.0",
     "@types/chai": "^4.3.5",
     "@types/chai-spies": "^1.0.3",
     "@types/mocha": "^10.0.2",