build: ignore `aio`/`docs-infra` commits in `changelog` gulp task (#25838)

PR Close #25838

tools/gulp-tasks/changelog.js

@@ -8,7 +8,17 @@
 
 module.exports = (gulp) => () => {
   const conventionalChangelog = require('gulp-conventional-changelog');
+  const ignoredScopes = [
+    'aio',
+    'docs-infra',
+  ];
+
   return gulp.src('CHANGELOG.md')
-      .pipe(conventionalChangelog({preset: 'angular'}))
+      .pipe(conventionalChangelog({preset: 'angular'}, {}, {
+        // Ignore commits that start with `<type>(<scope>)` for any of the ignored scopes.
+        extendedRegexp: true,
+        grep: `^[^(]+\\((${ignoredScopes.join('|')})\\)`,
+        invertGrep: true,
+      }))
       .pipe(gulp.dest('./'));
 };