Add missing @Uninterruptible.

Author: cstancu

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jfr/sampler/AbstractJfrExecutionSampler.java

@@ -170,6 +170,7 @@ protected static boolean isExecutionSamplingAllowedInCurrentThread() {
 
     protected abstract void updateInterval();
 
+    @Uninterruptible(reason = "Prevent VM operations that modify the recurring callbacks.")
     protected abstract void uninstall(IsolateThread thread);
 
     @Uninterruptible(reason = "The method executes during signal handling.", callerMustBe = true)