Remove support for Goerli testnet

As the Goerli testnet will become deprecated with end of year 2023 and we've
already migrated to Sepolia testnet, we'll no longer need the Goerli-related
code past that date.

Author: michalinacienciala

.github/workflows/contracts.yml

@@ -125,14 +125,7 @@ jobs:
 
       - name: Deploy contracts
         env:
-          # Using fake ternary expressions to decide which credentials to use,
-          # depending on chosen environment. Note: if `GOERLI_ETH_HOSTNAME_HTTP`
-          # is empty, the expression will be evaluated to
-          # `SEPOLIA_ETH_HOSTNAME_HTTP`'s value.
-          CHAIN_API_URL: |
-            ${{ inputs.github.event.inputs.environment == 'goerli'
-              && secrets.GOERLI_ETH_HOSTNAME_HTTP
-              || secrets.SEPOLIA_ETH_HOSTNAME_HTTP }}
+          CHAIN_API_URL: ${{ secrets.SEPOLIA_ETH_HOSTNAME_HTTP }}
           CONTRACT_OWNER_ACCOUNT_PRIVATE_KEY: ${{ secrets.TESTNET_ETH_CONTRACT_OWNER_PRIVATE_KEY }}
           KEEP_CONTRACT_OWNER_ACCOUNT_PRIVATE_KEY: ${{ secrets.TESTNET_ETH_CONTRACT_OWNER_PRIVATE_KEY }}
         run: yarn deploy --network ${{ github.event.inputs.environment }}
@@ -203,14 +196,7 @@ jobs:
       - name: Verify contracts on Etherscan
         env:
           ETHERSCAN_API_KEY: ${{ secrets.ETHERSCAN_API_KEY }}
-          # Using fake ternary expressions to decide which credentials to use,
-          # depending on chosen environment. Note: if `GOERLI_ETH_HOSTNAME_HTTP`
-          # is empty, the expression will be evaluated to
-          # `SEPOLIA_ETH_HOSTNAME_HTTP`'s value.
-          CHAIN_API_URL: |
-            ${{ inputs.github.event.inputs.environment == 'goerli'
-              && secrets.GOERLI_ETH_HOSTNAME_HTTP
-              || secrets.SEPOLIA_ETH_HOSTNAME_HTTP }}
+          CHAIN_API_URL: ${{ secrets.SEPOLIA_ETH_HOSTNAME_HTTP }}
         run: |
           yarn run hardhat --network ${{ github.event.inputs.environment }} \
             etherscan-verify --license GPL-3.0 --force-license
@@ -245,14 +231,7 @@ jobs:
 
       - name: Deploy contracts
         env:
-          # Using fake ternary expressions to decide which credentials to use,
-          # depending on chosen environment. Note: if `GOERLI_ETH_HOSTNAME_HTTP`
-          # is empty, the expression will be evaluated to
-          # `SEPOLIA_ETH_HOSTNAME_HTTP`'s value.
-          CHAIN_API_URL: |
-            ${{ inputs.github.event.inputs.environment == 'goerli'
-              && secrets.GOERLI_ETH_HOSTNAME_HTTP
-              || secrets.SEPOLIA_ETH_HOSTNAME_HTTP }}
+          CHAIN_API_URL: ${{ secrets.SEPOLIA_ETH_HOSTNAME_HTTP }}
           CONTRACT_OWNER_ACCOUNT_PRIVATE_KEY: ${{ secrets.DAPP_DEV_TESTNET_ETH_CONTRACT_OWNER_PRIVATE_KEY }}
           KEEP_CONTRACT_OWNER_ACCOUNT_PRIVATE_KEY: ${{ secrets.TESTNET_ETH_CONTRACT_OWNER_PRIVATE_KEY }}
         run: yarn deploy --network ${{ github.event.inputs.environment }}

deploy/00_resolve_nucypher_token.ts

@@ -22,7 +22,6 @@ const func: DeployFunction = async function (hre: HardhatRuntimeEnvironment) {
     // TODO: For testnets currently we deploy a stub contract. We should consider
     // switching to an actual contract.
     hre.network.name !== "sepolia" &&
-    hre.network.name !== "goerli" &&
     (!hre.network.tags.allowStubs ||
       (hre.network.config as HardhatNetworkConfig)?.forking?.enabled)
   ) {

deploy/07_deploy_token_staking.ts

@@ -17,7 +17,7 @@ const func: DeployFunction = async function (hre: HardhatRuntimeEnvironment) {
   ]
   const tokenStakingInitializerArgs = []
 
-  // TODO: Consider upgradable deployment also for goerli/sepolia.
+  // TODO: Consider upgradable deployment also for sepolia.
   let tokenStakingAddress
   if (hre.network.name == "mainnet") {
     const TokenStaking = await ethers.getContractFactory("TokenStaking")