ci: Stop running CI for Node.js 18 (#3353)

To reduce the number of concurrent jobs, we can stop running CI for
Node.js 18 (since it's EOL in a few days anyway).

Author: Mrtenz

.github/workflows/build-lint-test.yml

@@ -17,7 +17,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        node-version: [18.x, 20.x, 22.x]
+        node-version: [20.x, 22.x]
     steps:
       - name: Checkout and setup environment
         uses: MetaMask/action-checkout-and-setup@v1
@@ -139,7 +139,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        node-version: [18.x, 20.x, 22.x]
+        node-version: [20.x, 22.x]
         package-name: ${{ fromJson(needs.prepare.outputs.test-workspace-package-names) }}
     steps:
       - name: Checkout and setup environment
@@ -219,7 +219,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        node-version: [18.x, 20.x, 22.x]
+        node-version: [20.x, 22.x]
         package-name: ${{ fromJson(needs.prepare.outputs.e2e-workspace-package-names) }}
     steps:
       - name: Checkout and setup environment