Change default EVM version to Shanghai.

Co-authored-by: Rodrigo Q. Saramago <rodrigoqsaramago@gmail.com>

test/externalTests/uniswap.sh

@@ -83,8 +83,6 @@ function uniswap_test
     #   "revert SPL" is expected but the message is "reverted with reason string 'SPL'" in 2.5.0.
     # - Newer versions of ethereumjs/tx have an issue with 'gteHardfork()' method.
     neutralize_package_lock
-    yarn add hardhat@2.4.3
-    yarn add @ethereumjs/tx@3.1.3
 
     yarn install
     yarn add hardhat-gas-reporter

test/externalTests/yield-liquidator.sh

@@ -66,9 +66,10 @@ function yield_liquidator_test
     force_hardhat_unlimited_contract_size "$config_file" "$config_var"
     npm install
 
-    # 2.11.0 Hardhat release breaks contract compilation.
-    # TODO: remove when https://github.com/yieldprotocol/yield-liquidator-v2/issues/34 is addressed.
-    npm install hardhat@2.10.2
+    # The contract below is not used in any test and it depends on ISwapRouter which does not exists
+    # in the main repository.
+    # See: https://github.com/yieldprotocol/yield-liquidator-v2/blob/9a49d9a0e9398f6a6c07bad531e77d1001a1166f/src/swap_router.rs#L94
+    rm --force contracts/.YvBasicFlashLiquidator.sol
 
     replace_version_pragmas
     neutralize_packaged_contracts