[TSan] Fix CI test failures

I think this fix didn't get propagated in the transition from
llvm:stable to llvm-project:swift/master because the filename changed
from `lit.cfg` to `lit.cfg.py` at the same time.

rdar://56545824

Original commit:
  [TSan] Follow-up for my previous commit

  I enabled ignore_interceptors_accesses, but forgot to disable it for
  tests to avoid false negatives.

  apple-llvm-split-commit: 77a1e0d62108f1363fbe868b09eb53d42b923aae
  apple-llvm-split-dir: compiler-rt/

  (cherry picked from commit 67bb9b1)

Author: yln

compiler-rt/test/tsan/lit.cfg

@@ -28,6 +28,7 @@ if config.host_os == 'Darwin':
   # suppresses some races the tests are supposed to find. Let's run without this
   # setting, but turn it back on for Darwin tests (see Darwin/lit.local.cfg).
   default_tsan_opts += ':ignore_noninstrumented_modules=0'
+  default_tsan_opts += ':ignore_interceptors_accesses=0'
 
 # Platform-specific default TSAN_OPTIONS for lit tests.
 if default_tsan_opts: