ESQL: Fix lookup optimizer tests on release (elastic#118742) (elastic#118750)

Fix elastic#118721

* Skip corresponding optimizer tests if `LOOKUP JOIN` is disabled.
* Enable LogicalPlanOptimizerTests again.

(cherry picked from commit bb8503a)

# Conflicts:
#	muted-tests.yml

Author: alex-spies

muted-tests.yml

@@ -470,5 +470,3 @@ tests:
 - class: org.elasticsearch.index.engine.RecoverySourcePruneMergePolicyTests
   method: testPruneSome
   issue: https://github.com/elastic/elasticsearch/issues/118728
-- class: org.elasticsearch.xpack.esql.optimizer.LogicalPlanOptimizerTests
-  issue: https://github.com/elastic/elasticsearch/issues/118721

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/optimizer/LogicalPlanOptimizerTests.java

@@ -21,6 +21,7 @@
 import org.elasticsearch.xpack.esql.EsqlTestUtils;
 import org.elasticsearch.xpack.esql.TestBlockFactory;
 import org.elasticsearch.xpack.esql.VerificationException;
+import org.elasticsearch.xpack.esql.action.EsqlCapabilities;
 import org.elasticsearch.xpack.esql.analysis.Analyzer;
 import org.elasticsearch.xpack.esql.analysis.AnalyzerContext;
 import org.elasticsearch.xpack.esql.analysis.AnalyzerTestUtils;
@@ -4910,6 +4911,8 @@ public void testPlanSanityCheck() throws Exception {
     }
 
     public void testPlanSanityCheckWithBinaryPlans() throws Exception {
+        assumeTrue("Requires LOOKUP JOIN", EsqlCapabilities.Cap.JOIN_LOOKUP_V5.isEnabled());
+
         var plan = optimizedPlan("""
               FROM test
             | RENAME languages AS language_code
@@ -5913,6 +5916,8 @@ public void testLookupStats() {
      *     \_EsRelation[language_code][LOOKUP][language_code{f}#18, language_name{f}#19]
      */
     public void testLookupJoinPushDownFilterOnJoinKeyWithRename() {
+        assumeTrue("Requires LOOKUP JOIN", EsqlCapabilities.Cap.JOIN_LOOKUP_V5.isEnabled());
+
         String query = """
               FROM test
             | RENAME languages AS language_code
@@ -5954,6 +5959,8 @@ public void testLookupJoinPushDownFilterOnJoinKeyWithRename() {
      *     \_EsRelation[language_code][LOOKUP][language_code{f}#18, language_name{f}#19]
      */
     public void testLookupJoinPushDownFilterOnLeftSideField() {
+        assumeTrue("Requires LOOKUP JOIN", EsqlCapabilities.Cap.JOIN_LOOKUP_V5.isEnabled());
+
         String query = """
               FROM test
             | RENAME languages AS language_code
@@ -5996,6 +6003,8 @@ public void testLookupJoinPushDownFilterOnLeftSideField() {
      *       \_EsRelation[language_code][LOOKUP][language_code{f}#18, language_name{f}#19]
      */
     public void testLookupJoinPushDownDisabledForLookupField() {
+        assumeTrue("Requires LOOKUP JOIN", EsqlCapabilities.Cap.JOIN_LOOKUP_V5.isEnabled());
+
         String query = """
               FROM test
             | RENAME languages AS language_code
@@ -6039,6 +6048,8 @@ public void testLookupJoinPushDownDisabledForLookupField() {
      *       \_EsRelation[language_code][LOOKUP][language_code{f}#19, language_name{f}#20]
      */
     public void testLookupJoinPushDownSeparatedForConjunctionBetweenLeftAndRightField() {
+        assumeTrue("Requires LOOKUP JOIN", EsqlCapabilities.Cap.JOIN_LOOKUP_V5.isEnabled());
+
         String query = """
               FROM test
             | RENAME languages AS language_code
@@ -6090,6 +6101,8 @@ public void testLookupJoinPushDownSeparatedForConjunctionBetweenLeftAndRightFiel
      *       \_EsRelation[language_code][LOOKUP][language_code{f}#19, language_name{f}#20]
      */
     public void testLookupJoinPushDownDisabledForDisjunctionBetweenLeftAndRightField() {
+        assumeTrue("Requires LOOKUP JOIN", EsqlCapabilities.Cap.JOIN_LOOKUP_V5.isEnabled());
+
         String query = """
               FROM test
             | RENAME languages AS language_code