fix(ct): bug in GasPriceOracle test

Fixes a bug in the GasPriceOracle test suite that seems to only have had
an impact because hardhat got significantly faster between the current
iteration and the older one.

packages/contracts/test/contracts/L2/predeploys/OVM_GasPriceOracle.spec.ts

@@ -26,9 +26,9 @@ describe('OVM_GasPriceOracle', () => {
       await signer1.getAddress()
     )
 
-    OVM_GasPriceOracle.setOverhead(2750)
-    OVM_GasPriceOracle.setScalar(1500000)
-    OVM_GasPriceOracle.setDecimals(6)
+    await OVM_GasPriceOracle.setOverhead(2750)
+    await OVM_GasPriceOracle.setScalar(1500000)
+    await OVM_GasPriceOracle.setDecimals(6)
   })
 
   describe('owner', () => {