chore(integration): increase timeouts

Rationale: tests are passing on my machine for the parent to this commit,
but failing in github's CI

integration-tests/hardhat.config.ts

@@ -14,7 +14,7 @@ const config: HardhatUserConfig = {
     },
   },
   mocha: {
-    timeout: 50000,
+    timeout: 75_000,
   },
   solidity: {
     version: '0.8.9',

integration-tests/test/stress-tests.spec.ts

@@ -20,7 +20,7 @@ import simpleStorageJson from '../artifacts/contracts/SimpleStorage.sol/SimpleSt
 // Need a big timeout to allow for all transactions to be processed.
 // For some reason I can't figure out how to set the timeout on a per-suite basis
 // so I'm instead setting it for every test.
-const STRESS_TEST_TIMEOUT = 300_000
+const STRESS_TEST_TIMEOUT = 500_000
 
 describe('stress tests', () => {
   let env: OptimismEnv