Change the name of Postgresql to PostgreSQL

Author: Terran

babel/src/test/java/org/apache/calcite/test/BabelTest.java

@@ -497,7 +497,7 @@ private void checkSqlResult(String funLibrary, String query, String result) {
 
   /** Test case for
    * <a href="https://issues.apache.org/jira/browse/CALCITE-7337">[CALCITE-7337]
-   * Add age function (enabled in Postgresql library)</a>. */
+   * Add age function (enabled in PostgreSQL library)</a>. */
   @Test void testAgeFunction() {
     checkSqlResult("postgresql",
         "SELECT AGE(timestamp '2023-12-25', timestamp '2020-01-01') FROM (VALUES (1)) t",

testkit/src/main/java/org/apache/calcite/test/SqlOperatorTest.java

@@ -6950,7 +6950,7 @@ void checkRegexpExtract(SqlOperatorFixture f0, FunctionAlias functionAlias) {
 
   /** Test case for
    * <a href="https://issues.apache.org/jira/browse/CALCITE-7337">[CALCITE-7337]
-   * Add age function (enabled in Postgresql library)</a>. */
+   * Add age function (enabled in PostgreSQL library)</a>. */
   @Test void testAgePg() {
     final SqlOperatorFixture f0 = fixture();
     f0.checkFails("^age(timestamp '2023-12-25', timestamp '2020-01-01')^",