Finalize test migration: remove legacy dependencies and test helpers (#4797)

.github/ISSUE_TEMPLATE/bug_report.md

@@ -10,7 +10,7 @@ about: Report a bug in OpenZeppelin Contracts
 
 **💻 Environment**
 
-<!-- Tell us what version of OpenZeppelin Contracts you're using, and how you're using it: Truffle, Remix, etc. -->
+<!-- Tell us what version of OpenZeppelin Contracts you're using, and how you're using it: Hardhat, Remix, etc. -->
 
 **📝 Details**
 

.github/workflows/checks.yml

@@ -34,8 +34,6 @@ jobs:
       - uses: actions/checkout@v4
       - name: Set up environment
         uses: ./.github/actions/setup
-      - name: Compile contracts # TODO: Remove after migrating tests to ethers
-        run: npm run compile
       - name: Run tests and generate gas report
         run: npm run test
       - name: Check linearisation of the inheritance graph
@@ -64,8 +62,6 @@ jobs:
           cp -rnT contracts lib/openzeppelin-contracts/contracts
       - name: Transpile to upgradeable
         run: bash scripts/upgradeable/transpile.sh
-      - name: Compile contracts # TODO: Remove after migrating tests to ethers
-        run: npm run compile
       - name: Run tests
         run: npm run test
       - name: Check linearisation of the inheritance graph
@@ -94,8 +90,6 @@ jobs:
       - uses: actions/checkout@v4
       - name: Set up environment
         uses: ./.github/actions/setup
-      - name: Compile contracts # TODO: Remove after migrating tests to ethers
-        run: npm run compile
       - name: Run coverage
         run: npm run coverage
       - uses: codecov/codecov-action@v3