Use DBMS_SESSION.SLEEP instead of DBMS_LOCK.SLEEP where available

DBMS_SESSION.SLEEP (available since Oracle 18c) does not require a
separate grant from SYS, unlike DBMS_LOCK.SLEEP.

Remove the blanket "grant execute on dbms_lock to hr" from the shared
user setup SQL. The spec already uses DBMS_SESSION.SLEEP on Oracle
18c+ and falls back to DBMS_LOCK.SLEEP on older versions. Add the
DBMS_LOCK grant only to the 11g workflow which still needs it.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: yahonda

.github/workflows/test_11g.yml

@@ -84,6 +84,9 @@ jobs:
     - name: Create database user
       run: |
         ./ci/setup_accounts.sh
+    - name: Grant execute on DBMS_LOCK for Oracle 11g
+      run: |
+        echo "GRANT EXECUTE ON DBMS_LOCK TO hr;" | sqlplus system/${DATABASE_SYS_PASSWORD}@${DATABASE_NAME}
     - name: Disable ActiveRecord for TruffleRuby
       run: |
         echo "NO_ACTIVERECORD=true" >> $GITHUB_ENV

spec/support/unlock_and_setup_hr_user.sql

@@ -1,4 +1,3 @@
 create user hr identified by hr;
 alter user hr identified by hr account unlock;
 grant dba to hr;
-grant execute on dbms_lock to hr;