Enable Python shader trace validation by default

Author: Zorro666

util/test/rdtest/testcase.py

@@ -619,7 +619,7 @@ def check_final_backbuffer(self):
 
         log.success("Backbuffer is identical to reference")
 
-    def process_trace(self, trace: rd.ShaderDebugTrace, validate: bool = False):
+    def process_trace(self, trace: rd.ShaderDebugTrace, validate: bool = True):
         variables = {}
         cycles = 0
         allChanges = []