Run tests on Node.js 15 (#9494)

* Run tests on `Node.js` 15

* Switch `exclude` to `include`

.github/workflows/dev-test.yml

@@ -28,6 +28,8 @@ jobs:
             ENABLE_CODE_COVERAGE: true
             FULL_TEST: true
             CHECK_TEST_PARSERS: true
+          - os: "ubuntu-latest"
+            node: "15"
         exclude:
           - os: "macos-latest"
             node: "12"

.github/workflows/prod-test.yml

@@ -91,6 +91,8 @@ jobs:
           - os: "ubuntu-latest"
             node: "14"
             FULL_TEST: true
+          - os: "ubuntu-latest"
+            node: "15"
         exclude:
           - os: "macos-latest"
             node: "12"