ci: activate pipefail option in order to fix error from ansible-lint

The error was:
306 Shells that use pipes should set the pipefail option
src/main/scripts/ci/ansible/deploy.yml:41
Task/Handler: Ensuring whether Liquibase migrations are valid

Should be in 6162b3c commit.

See https://ansible-lint.readthedocs.io/en/latest/rules/risky-shell-pipe/

Relate to #383

Author: php-coder

Diff for: src/main/scripts/ci/ansible/deploy.yml

@@ -41,10 +41,12 @@
   - name: Ensuring whether Liquibase migrations are valid
     shell: |
       set -eu
+      set -o pipefail
       eval "$(sed -n '/^[A-Z]/s||export &|p' mystamps.conf)"
       java $JAVA_OPTS -jar mystamps-candidate.war liquibase validate
     args:
       chdir: /data/mystamps
+      executable: /bin/bash
     changed_when: False
     register: liquibase_validate