Fix the phpcpd exclusions to "Tests" and add it to composer

Also, make the check to really fail the build if there are
cases found, coz it's not useful to have it failing all the
time without noticing.

Author: stronk7

.github/workflows/phpcs.yml

@@ -24,7 +24,7 @@ jobs:
           extensions: ${{ matrix.extensions }}
           ini-values: pcov.directory=moodle
           coverage: pcov
-          tools: composer, phpcpd
+          tools: composer
 
       - name: Install composer dependencies
         run: |
@@ -36,9 +36,8 @@ jobs:
           ./vendor/bin/phplint
 
       - name: PHP Copy/Paste Detector
-        continue-on-error: true # This step will show errors but will not fail
         if: ${{ always() }}
-        run: phpcpd --exclude moodle/tests moodle
+        run: ./vendor/bin/phpcpd --exclude moodle/Tests moodle
 
       - name: Run phpunit
         if: ${{ always() }}

composer.json

@@ -41,7 +41,8 @@
         "mikey179/vfsstream": "^1.6",
         "overtrue/phplint": "^3.0",
         "phpmd/phpmd": "^2.11",
-        "thor-juhasz/phpunit-coverage-check": "^0.3.0"
+        "thor-juhasz/phpunit-coverage-check": "^0.3.0",
+        "sebastian/phpcpd": "^6.0"
     },
     "replace": {
         "moodlehq/moodle-local_codechecker": "3.1.0"