fix(ant): Include csv in Export.setFormat's unsupported-format message

setFormat(String) has always accepted "csv" via isSupportedFormat(), but
its IllegalArgumentException message listed only 'flat'(default), 'xml',
'dtd', 'xls', and 'yml' - omitting the one format this area's other bugs
(issue 808) are specifically about, and misleading anyone who hit the
exception into thinking csv wasn't supported.

Refs: 808

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QqQTzFd5qsXiMTpFsReD12

Author: jeffjensen

src/changes/changes.xml

@@ -86,6 +86,9 @@
       <action dev="jeffjensen" type="fix" issue="808" system="github" due-to="jeffjensen">
           Fix the Ant export step rejecting format="CSV" in uppercase and leaving an empty output file behind for unsupported formats. Also, an unsupported format is now rejected before the database connection is queried for the export dataset, instead of after, since format validity doesn't depend on the connection.
       </action>
+      <action dev="jeffjensen" type="fix" issue="808" system="github" due-to="jeffjensen">
+          Fix Export.setFormat()'s IllegalArgumentException message omitting 'csv' from the list of valid formats, even though csv has always been accepted.
+      </action>
       <action dev="jeffjensen" type="fix" issue="809" system="github" due-to="jeffjensen">
           DefaultPrepAndExpectedTestCase.postTest now attaches a verify failure as suppressed on the cleanup exception that deliberately shadows it, instead of losing it.
       </action>

src/main/java/org/dbunit/ant/Export.java

@@ -114,7 +114,7 @@ public void setFormat(String format)
         }
         else
         {
-            throw new IllegalArgumentException("Type must be one of: 'flat'(default), 'xml', 'dtd', 'xls' or 'yml' but was: " + format);
+            throw new IllegalArgumentException("Type must be one of: 'flat'(default), 'xml', 'dtd', 'csv', 'xls' or 'yml' but was: " + format);
         }
     }