chore(workflow): add comment about node 22 test coverage exclusion

Author: erisu

.github/workflows/ci.yml

@@ -70,13 +70,16 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-26]
+        # The "--test-coverage-exclude" flag is supported in v22.5.0 and later.
+        # By default, all matching test files are excluded from the coverage report.
+        # Only Node.js 22.x requires explicitly declaring test file exclusions.
         node:
           - version: 20.x
             options: ''
           - version: 22.x
             options: --test-coverage-exclude=test/**/*.js
           - version: 24.x
-            options: --test-coverage-exclude=test/**/*.js
+            options: ''
 
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2