[Spark] Disable flaky DeltaLogSuite unit test that relies on filesyst…

…em behavior (#2761)

#### Which Delta project/connector is this regarding?
- [x] Spark
- [ ] Standalone
- [ ] Flink
- [ ] Kernel
- [ ] Other (fill in here)

## Description
Mark the flaky `"DeltaLog should throw exception when unable to create
log directory with silent filesystem failure"` DeltaLogSuite test as
ignored.

## How was this patch tested?
N/A. CI tests.

## Does this PR introduce _any_ user-facing changes?
No

spark/src/test/scala/org/apache/spark/sql/delta/DeltaLogSuite.scala

@@ -689,7 +689,7 @@ class DeltaLogSuite extends QueryTest
     }
   }
 
-  test("DeltaLog should throw exception when unable to create log directory " +
+  ignore("DeltaLog should throw exception when unable to create log directory " +
     "with silent filesystem failure") {
     withTempDir { dir =>
       val path = dir.getCanonicalPath