CI: make lint-commits part of xlint.sh

* CI will stop whenever a step is failing.
* We always want to enforce commit message lint
* `xlint` is reporting some false positive for license with " WITH "

Let's make the lint-commits part of xlint.sh

.github/workflows/build.yaml

@@ -22,8 +22,6 @@ jobs:
       - run: common/travis/fetch-xbps.sh
       - run: common/travis/fetch-xtools.sh
       - run: common/travis/xlint.sh
-      # GitHub Action create a merge commit, ignore it
-      - run: common/scripts/lint-commits FETCH_HEAD HEAD^2
 
   # Build changed packages.
   build: