Fix flaky test DeprecatedJoinMapperTest

[bee0511]

What changed

Replaced containsExactly(...) with containsOnly(...) to avoid assuming deterministic field order in rows/Maps.

Why

The test failed intermittently because Map iteration order is not guaranteed. NonDex exposed this by randomizing iteration order.

How to reproduce

Run the test repeatedly with NonDex:

mvn -pl . edu.illinois:nondex-maven-plugin:2.1.7:nondex -Dtest=examples.kotlin.mybatis3.joins.DeprecatedJoinMapperTest -Drat.skip

You will see failures like:

Tests run: 1, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 1.944 s <<< FAILURE! -- in examples.kotlin.mybatis3.joins.DeprecatedJoinMapperTest
examples.kotlin.mybatis3.joins.DeprecatedJoinMapperTest.testFullJoinWithoutAliases -- Time elapsed: 0.419 s <<< FAILURE!
java.lang.AssertionError: 

Actual and expected have the same elements but not in the same order, at index 0 actual element was:
  "QUANTITY"=6
whereas expected element was:
  "ORDER_ID"=2

	at examples.kotlin.mybatis3.joins.DeprecatedJoinMapperTest.testFullJoinWithoutAliases(DeprecatedJoinMapperTest.kt:284)
	at java.base/java.lang.reflect.Method.invoke(Method.java:569)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)

How tested

Verified with the same NonDex runs; no further order-related failures occurred.

Tests fixed

examples.kotlin.mybatis3.joins.DeprecatedJoinMapperTest.testFullJoinWithoutAliases
examples.kotlin.mybatis3.joins.DeprecatedJoinMapperTest.testLeftJoinWithAliases
examples.kotlin.mybatis3.joins.DeprecatedJoinMapperTest.testLeftJoinWithoutAliases
examples.kotlin.mybatis3.joins.DeprecatedJoinMapperTest.testLeftJoinWithSubQuery
examples.kotlin.mybatis3.joins.DeprecatedJoinMapperTest.testRightJoinWithAliases
examples.kotlin.mybatis3.joins.DeprecatedJoinMapperTest.testRightJoinWithoutAliases
examples.kotlin.mybatis3.joins.DeprecatedJoinMapperTest.testRightJoinWithSubQuery

[bee0511]

I found other tests within this class also have similar issue. I will update the PR information.