[CI] FilesEntitlementsValidationTests testValidationFailForRead failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic #8071 / openjdk21_checkpart1_java-fips-matrix
• elasticsearch-periodic #8071 / openjdk23_checkpart1_java-matrix
• elasticsearch-periodic #8071 / openjdk21_checkpart1_java-matrix
• elasticsearch-periodic #8065 / openjdk23_checkpart1_java-matrix
• elasticsearch-periodic #8065 / openjdk21_checkpart1_java-matrix
• elasticsearch-periodic #8065 / openjdk21_checkpart1_java-fips-matrix
• elasticsearch-periodic #8059 / openjdk21_checkpart1_java-fips-matrix
• elasticsearch-periodic #8059 / openjdk21_checkpart1_java-matrix
• elasticsearch-periodic #8059 / openjdk23_checkpart1_java-matrix
• elasticsearch-periodic #8053 / openjdk21_checkpart1_java-fips-matrix

Reproduction Line:

./gradlew ":libs:entitlement:test" --tests "org.elasticsearch.entitlement.initialization.FilesEntitlementsValidationTests.testValidationFailForWrite" -Dtests.seed=F8E915172A118973 -Dtests.locale=luy-KE -Dtests.timezone=Asia/Qostanay -Druntime.java=21 -Dtests.fips.enabled=true

Applicable branches:
9.0

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

junit.framework.AssertionFailedError: Unexpected exception type, expected IllegalArgumentException but got java.security.AccessControlException: access denied ("java.io.FilePermission" "/opt/buildkite-agent/.java/openjdk21/conf" "read")

Issue Reasons:

• [9.0] 3 consecutive failures in test testValidationFailForRead
• [9.0] 5 consecutive failures in step openjdk21_checkpart1_java-fips-matrix
• [9.0] 5 consecutive failures in step openjdk23_checkpart1_java-matrix
• [9.0] 5 consecutive failures in step openjdk21_checkpart1_java-matrix
• [9.0] 15 failures in test testValidationFailForRead (11.8% fail rate in 127 executions)
• [9.0] 5 failures in step openjdk21_checkpart1_java-fips-matrix (100.0% fail rate in 5 executions)
• [9.0] 5 failures in step openjdk23_checkpart1_java-matrix (100.0% fail rate in 5 executions)
• [9.0] 5 failures in step openjdk21_checkpart1_java-matrix (100.0% fail rate in 5 executions)
• [9.0] 5 failures in pipeline elasticsearch-periodic (100.0% fail rate in 5 executions)

Note:
This issue was created using new test triage automation. Please report issues or feedback to es-delivery.

[elasticsearchmachine]

Pinging @elastic/es-core-infra (Team:Core/Infra)

[ldematte]

Fixed by #127789