Use gradle, not ./gradlew

.gitlab-ci.yml

 image: gradle:7.2.0-jdk16-hotspot
 
-before_script:
-  - export GRADLE_USER_HOME=`pwd`/.gradle
+#before_script:
+#  - export GRADLE_USER_HOME=`pwd`/.gradle
 
-cache:
-  paths:
-    - .gradle/wrapper
-    - .gradle/caches
+#cache:
+#  paths:
+#    - .gradle/wrapper
+#    - .gradle/caches
 
 build:
   stage: build
   script:
-    - ./gradlew -Pci=gitlab build
+    - gradle -Pci=gitlab build
   artifacts:
     paths:
     - public/lectures/build/docs
 
 pages:
   script:
-    - ./gradlew -Pci=gitlab build
+    - gradle -Pci=gitlab build
     - cp -r lectures/build/docs/asciidoc public/lectures