Fix flaky test TestIgniteStore#testQueryKeyRange in gora-ignite

[ndeneh93]

What is the purpose of this PR

• Fixes the flaky test org.apache.gora.ignite.store.TestIgniteStore#testQueryKeyRange in the gora-ignite module.
• The test previously assumed deterministic iteration order from Apache Ignite, causing nondeterministic failures.

Why the test fails**

• The test executes a query with a key range 2L → 5L and asserts that the keys are [2, 3, 4].
• Ignite does not guarantee iteration order, so the test sometimes returns [3,4,2], [4,2,3], etc.

How to reproduce the test failure**

• Run normally:
  mvn -pl gora-ignite test -Dtest=org.apache.gora.ignite.store.TestIgniteStore#testQueryKeyRange
• Run with NonDex for 30 executions:
  mvn -pl gora-ignite edu.illinois:nondex-maven-plugin:2.1.1:nondex
  -Dtest=org.apache.gora.ignite.store.TestIgniteStore#testQueryKeyRange
  -DnondexRuns=30
• Some runs will fail if the fix is not applied.

Expected results**

• The test should always pass, regardless of key order.

Actual results**

• Before the fix, the test passes intermittently depending on key iteration order.

Description of fix**

• Enforces deterministic ordering by sorting the result keys before assertion:

  Collections.sort(keys);
  assertEquals(Arrays.asList(2L, 3L, 4L), keys);

• Ensures deterministic results without modifying the system under test.

Review Questions & Answers

• Is this test still flaky? No, verified by repeated mvn test and NonDex runs.
• Any existing open PRs for this test? No.
• Any closed/rejected PRs? PR Fix non-deterministic behaviors in IgniteSQLBuilder and IgniteStoreMetadataAnalyzer #296 in apache/gora addressed it but assumed deterministic ordering and was rejected.