[test](external) Add restart_fe tag to test suites (#48181)

This change adds the `restart_fe` tag to the
`test_upgrade_lower_case_catalog` and
`test_upgrade_lower_case_catalog_prepare` test suites, indicating that
the Frontend needs to be restarted as part of these tests. Additionally,
it removes redundant test cases for showing databases and tables, as
these verifications are now handled elsewhere.

regression-test/suites/external_table_p0/lower_case/upgrade/load.groovy

@@ -19,7 +19,7 @@ import java.util.concurrent.Executors
 import java.util.concurrent.TimeUnit
 import org.awaitility.Awaitility
 
-suite("test_upgrade_lower_case_catalog_prepare", "p0,external,doris,external_docker,external_docker_doris") {
+suite("test_upgrade_lower_case_catalog_prepare", "p0,external,doris,external_docker,external_docker_doris,restart_fe") {
 
     String jdbcUrl = context.config.jdbcUrl
     String jdbcUser = "test_upgrade_lower_case_catalog_user"
@@ -89,29 +89,6 @@ suite("test_upgrade_lower_case_catalog_prepare", "p0,external,doris,external_doc
         )"""
 
     wait_table_sync("test_upgrade_lower_case_catalog.upgrade_lower_case_catalog_lower")
-    test {
-        sql """show databases from test_upgrade_lower_case_catalog"""
-
-        // Verification results include external_test_lower and external_test_UPPER
-        check { result, ex, startTime, endTime ->
-            def expectedDatabases = ["upgrade_lower_case_catalog_lower", "upgrade_lower_case_catalog_upper"]
-            expectedDatabases.each { dbName ->
-                assertTrue(result.collect { it[0] }.contains(dbName), "Expected database '${dbName}' not found in result")
-            }
-        }
-    }
-
-    test {
-        sql """show tables from test_upgrade_lower_case_catalog.upgrade_lower_case_catalog_lower"""
-
-        // Verification results include lower and UPPER
-        check { result, ex, startTime, endTime ->
-            def expectedTables = ["lower", "upper"]
-            expectedTables.each { tableName ->
-                assertTrue(result.collect { it[0] }.contains(tableName), "Expected table '${tableName}' not found in result")
-            }
-        }
-    }
 
     qt_sql_test_upgrade_lower_case_catalog_1 "select * from test_upgrade_lower_case_catalog.upgrade_lower_case_catalog_lower.lower"
     qt_sql_test_upgrade_lower_case_catalog_2 "select * from test_upgrade_lower_case_catalog.upgrade_lower_case_catalog_lower.upper"

regression-test/suites/external_table_p0/lower_case/upgrade/test_upgrade_lower_case_catalog.groovy

@@ -15,7 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-suite("test_upgrade_lower_case_catalog", "p0,external,doris,external_docker,external_docker_doris") {
+suite("test_upgrade_lower_case_catalog", "p0,external,doris,external_docker,external_docker_doris,restart_fe") {
 
     test {
         sql """show databases from test_upgrade_lower_case_catalog"""