Tests: Oracle CI, limit connections and prepared statements for oracle CI test

.github/workflows/oracle.yml

@@ -35,4 +35,4 @@ jobs:
           ~/.m2
         key: build-${{ env.cache-name }}
     - name: oracle
-      run: mvn -T 1C clean test -Dprops.file=testconfig/ebean-oracle.properties
+      run: mvn -T 1 clean test -Dprops.file=testconfig/ebean-oracle.properties

ebean-test/testconfig/ebean-oracle.properties

@@ -2,4 +2,5 @@ ebean.test.platform=oracle
 ebean.test.dbName=test_eb
 datasource.default=oracle
 ebean.lengthCheck=utf8
-datasource.oracle.pstmtCacheSize=100
+datasource.oracle.pstmtCacheSize=50
+datasource.oracle.maxConnections=20