Add retry around flaky test

Author: alexarchambault

frontend/src/test/scala/bloop/bsp/BspCompileSpec.scala

@@ -240,6 +240,11 @@ class BspCompileSpec(
   testNonWindows(
     "create orphan client classes directory and make sure loading a BSP session cleans it up"
   ) {
+    TestUtil.retry() {
+      orphanClientClassesDirBspSessionCleanUpTest()
+    }
+  }
+  def orphanClientClassesDirBspSessionCleanUpTest(): Unit = {
     TestUtil.withinWorkspace { workspace =>
       val sources = List(
         """/main/scala/Foo.scala