[lldb] Fix TestFrameLanguageCommands.py build (llvm#141829)

The use of `-lobjc` resulted in this test failing to build on Linux. The
flag is not necessary, this removes the flag with the expectation it
will fix the test on Linux.
(cherry-picked from commit e653dc9)

Author: kastiglione

lldb/test/API/commands/command/language/Makefile

@@ -1,4 +1,3 @@
 OBJCXX_SOURCES := main.mm
 CXX_SOURCES := lib.cpp
-LD_EXTRAS := -lobjc
 include Makefile.rules