Fix mvn build in docs.sh and use proper JDK17 img

Author: ferenc-csaky

.github/workflows/docs.sh

@@ -18,7 +18,7 @@
 ################################################################################
 set -e
 
-export JAVA_HOME=$JAVA_HOME_11_X64
+export JAVA_HOME=$JAVA_HOME_17_X64
 
 # setup hugo
 HUGO_REPO=https://github.com/gohugoio/hugo/releases/download/v0.104.0/hugo_extended_0.104.0_Linux-64bit.tar.gz

.github/workflows/docs.yaml

@@ -49,7 +49,7 @@ jobs:
           fi
       - name: Build documentation
         run: |
-          docker run  --rm --volume "$PWD:/root/flink-kubernetes-operator" chesnay/flink-ci:java_8_11 bash -c "cd /root/flink-kubernetes-operator && ./.github/workflows/docs.sh"
+          docker run  --rm --volume "$PWD:/root/flink-kubernetes-operator" chesnay/flink-ci:java_8_11_17_maven_386 bash -c "cd /root/flink-kubernetes-operator && ./.github/workflows/docs.sh"
       - name: Upload documentation
         uses: ./.github/actions/rsync-deployments
         with: