[cross-project-tests] Use lit internal shell (llvm#203138)

Author: boomanaiden154

cross-project-tests/lit.cfg.py

@@ -16,7 +16,7 @@
 config.name = "cross-project-tests"
 
 # testFormat: The test format to use to interpret tests.
-config.test_format = lit.formats.ShTest(not llvm_config.use_lit_shell)
+config.test_format = lit.formats.ShTest()
 
 # suffixes: A list of file extensions to treat as test files.
 config.suffixes = [".c", ".cl", ".cpp", ".m", ".test"]