All tests in ExternalDistributedResilienceIT and ExternalDistributedStressIT fail in the release-tests pipeline (-Dbuild.snapshot=false).

Failing tests (9):

ExternalDistributedResilienceIT:

• testNoFaultQuerySucceeds
• testTransient500RecoveryDuringDistributedQuery
• testTransient503RecoveryDuringDistributedQuery
• testConnectionResetRecoveryDuringDistributedQuery
• testPathFilteredFaultsOnlyAffectParquetReads

ExternalDistributedStressIT:

• testManyUniformSplits
• testManyUniformSplitsWithAggregation
• testManyUniformSplitsWithTopN
• testHeterogeneousSplitSizes

Reproduce:

./gradlew :x-pack:plugin:esql:qa:server:multi-node:javaRestTest --tests "org.elasticsearch.xpack.esql.qa.multi_node.ExternalDistributedResilienceIT" -Dbuild.snapshot=false -Dtests.jvm.argline="-Dbuild.snapshot=false"
./gradlew :x-pack:plugin:esql:qa:server:multi-node:javaRestTest --tests "org.elasticsearch.xpack.esql.qa.multi_node.ExternalDistributedStressIT" -Dbuild.snapshot=false -Dtests.jvm.argline="-Dbuild.snapshot=false"

Root cause: The EXTERNAL keyword is not recognized in non-snapshot builds. All queries fail with:

ParsingException: line 1:1: mismatched input 'EXTERNAL' expecting {, 'row', 'from', 'ts', 'promql', 'set', 'show'}

These test classes were added in #144277 without a snapshot build guard (e.g. assumeTrue(Build.current().isSnapshot())).

Build scan: https://gradle-enterprise.elastic.co/s/ycfjac6d2qhvi
Observed in: #144470