[compiler-rt] remove unused default in compiler-rt lit tests (llvm#143738)

In llvm#143183 was mistakenly added
a default value to `python_root_dir` in lit tests of compiler-rt.

This is unused by the lit tests of compiler-rt, as it was meant to be
used by `lldb`.

This patch removes this change.

Author: charles-zablit

compiler-rt/test/lit.common.configured.in

@@ -25,7 +25,6 @@ set_default("gold_executable", "@GOLD_EXECUTABLE@")
 set_default("clang", "@COMPILER_RT_RESOLVED_TEST_COMPILER@")
 set_default("compiler_id", "@COMPILER_RT_TEST_COMPILER_ID@")
 set_default("python_executable", "@Python3_EXECUTABLE@")
-set_default("python_root_dir", "@Python3_ROOT_DIR@")
 set_default("compiler_rt_debug", @COMPILER_RT_DEBUG_PYBOOL@)
 set_default("compiler_rt_intercept_libdispatch", @COMPILER_RT_INTERCEPT_LIBDISPATCH_PYBOOL@)
 set_default("compiler_rt_output_dir", "@COMPILER_RT_RESOLVED_OUTPUT_DIR@")