[6.8] Mute CertificateGenerateToolTest.testGeneratingSignedCertificates() on Java 8 (#73586)

This issue is tracked in #72639 which suffers the same JDK bug as #72359.

This commit backport the mute 9a655b5 to 6.8

Author: tlrx

x-pack/plugin/security/cli/src/test/java/org/elasticsearch/xpack/security/cli/CertificateGenerateToolTests.java

@@ -8,6 +8,7 @@
 import com.google.common.jimfs.Configuration;
 import com.google.common.jimfs.Jimfs;
 import org.bouncycastle.asn1.DLTaggedObject;
+import org.elasticsearch.bootstrap.JavaVersion;
 import org.elasticsearch.core.internal.io.IOUtils;
 import org.bouncycastle.asn1.ASN1ObjectIdentifier;
 import org.bouncycastle.asn1.ASN1Sequence;
@@ -263,6 +264,8 @@ public void testGeneratingCsr() throws Exception {
     }
 
     public void testGeneratingSignedCertificates() throws Exception {
+        assumeFalse("JDK bug JDK-8266279, https://github.com/elastic/elasticsearch/issues/72639",
+            JavaVersion.current().compareTo(JavaVersion.parse("8")) == 0);
         Path tempDir = initTempDir();
         Path outputFile = tempDir.resolve("out.zip");
         Path instanceFile = writeInstancesTo(tempDir.resolve("instances.yml"));