Fix some unit test failure in ExternalSSTFileBasicTest (#11070)

Summary:
valgrind build for `ExternalSSTFileBasicTest/ExternalSSTFileBasicTest.IngestFileWithMixedValueType` and `ExternalSSTFileBasicTest/ExternalSSTFileBasicTest.IngestFileWithGlobalSeqnoPickedSeqno` started failing (see error message in T141554665). I could not repro but I suspect it is due to file ingestion range overlapping with ongoing compaction, which caused a new global seqno being assigned after https://github.com/facebook/rocksdb/issues/10988.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11070

Test Plan: monitor future valgrind tests result.

Reviewed By: hx235

Differential Revision: D42319056

Pulled By: cbi42

fbshipit-source-id: acbcd841a2a15e36b278f39ba514f4b9a6ee43ca

db/external_sst_file_basic_test.cc

@@ -694,6 +694,7 @@ TEST_P(ExternalSSTFileBasicTest, IngestFileWithGlobalSeqnoPickedSeqno) {
   bool verify_checksums_before_ingest = std::get<1>(GetParam());
   do {
     Options options = CurrentOptions();
+    options.disable_auto_compactions = true;
     DestroyAndReopen(options);
     std::map<std::string, std::string> true_data;
 
@@ -928,6 +929,7 @@ TEST_P(ExternalSSTFileBasicTest, IngestFileWithMixedValueType) {
   bool verify_checksums_before_ingest = std::get<1>(GetParam());
   do {
     Options options = CurrentOptions();
+    options.disable_auto_compactions = true;
     options.merge_operator.reset(new TestPutOperator());
     DestroyAndReopen(options);
     std::map<std::string, std::string> true_data;