Fix flaky TestInternalMixedCatalogService by hardening test cleanup (#4165)

* Fix flaky TestInternalMixedCatalogService by hardening test cleanup

When a test method fails mid-way after creating a table but before
dropping it, the @AfterEach cleanup could not drop the non-empty
database.  This left residual state that caused cascading failures
in subsequent nested test classes (Database already exists, assertion
on listDatabases().isEmpty(), etc.).

- CompatibilityCatalogTests.cleanDatabase: drop residual table before
  dropping database, wrap both in try-catch
- TestTableCommit.after: guard dropTable with tableExists check, wrap
  in try-catch to prevent cascading cleanup failures

Signed-off-by: Jiwon Park <jpark92@outlook.kr>

* Wrap dropDatabase in try-catch in TestTableOperation cleanup

Add missing try-catch around dropDatabase in TestTableOperation.after()
for consistency with TestTableCommit and CompatibilityCatalogTests
cleanup methods.

Signed-off-by: Jiwon Park <jpark92@outlook.kr>

---------

Signed-off-by: Jiwon Park <jpark92@outlook.kr>

Author: j1wonpark

amoro-ams/src/test/java/org/apache/amoro/server/TestInternalMixedCatalogService.java

@@ -197,7 +197,11 @@ public void after() {
       } catch (Exception e) {
         LOG.warn("Failed to drop table during cleanup", e);
       }
-      catalog.dropDatabase(database);
+      try {
+        catalog.dropDatabase(database);
+      } catch (Exception e) {
+        LOG.warn("Failed to drop database during cleanup", e);
+      }
     }
 
     @ParameterizedTest(name = "CatalogTableOperationTest[withPrimaryKey={0}]")
@@ -257,8 +261,18 @@ public void before() {
 
     @AfterEach
     public void after() {
-      catalog.dropTable(tableIdentifier, true);
-      catalog.dropDatabase(database);
+      try {
+        if (catalog.tableExists(tableIdentifier)) {
+          catalog.dropTable(tableIdentifier, true);
+        }
+      } catch (Exception e) {
+        LOG.warn("Failed to drop table during cleanup", e);
+      }
+      try {
+        catalog.dropDatabase(database);
+      } catch (Exception e) {
+        LOG.warn("Failed to drop database during cleanup", e);
+      }
     }
 
     @ParameterizedTest(name = "TableCommitTest[withPrimaryKey={0}]")
@@ -320,7 +334,18 @@ public void setupTest() {
 
     @AfterEach
     public void cleanDatabase() {
-      catalog.dropDatabase(database);
+      try {
+        if (catalog.tableExists(tableIdentifier)) {
+          catalog.dropTable(tableIdentifier, true);
+        }
+      } catch (Exception e) {
+        LOG.warn("Failed to drop table during cleanup", e);
+      }
+      try {
+        catalog.dropDatabase(database);
+      } catch (Exception e) {
+        LOG.warn("Failed to drop database during cleanup", e);
+      }
     }
 
     @ParameterizedTest(name = "Test-NewCatalog-Load-HistoricalTable[withPrimaryKey={0}]")