[libc++/abi/unwind] Rename Lit features for no exceptions to 'no-exceptions'

Instead of having different names for the same Lit feature accross code
bases, use the same name everywhere. This NFC commit is in preparation
for a refactor where all three projects will be using the same Lit
feature detection logic, and hence it won't be convenient to use
different names for the feature.

Differential Revision: https://reviews.llvm.org/D78370

GitOrigin-RevId: 8c61114c53dcd6139a4a750925b91ed9bcf4178c
diff --git a/test/libunwind/test/config.py b/test/libunwind/test/config.py
index 41ca3f9..36501f2 100644
--- a/test/libunwind/test/config.py
+++ b/test/libunwind/test/config.py
@@ -36,7 +36,7 @@
     def configure_features(self):
         super(Configuration, self).configure_features()
         if not self.get_lit_bool('enable_exceptions', True):
-            self.config.available_features.add('libcxxabi-no-exceptions')
+            self.config.available_features.add('no-exceptions')
         if self.get_lit_bool('arm_ehabi', False):
             self.config.available_features.add('libunwind-arm-ehabi')