Fix python/ir/auto_location.py test on Windows (llvm#156711)

Initially found in:
llvm#151246 (comment)

To fix:
```txt
******************** TEST 'MLIR :: python/ir/auto_location.py' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
"C:/hostedtoolcache/windows/Python/3.11.9/x64/python3.exe" D:\a\triton\triton\llvm-project\mlir\test\python\ir\auto_location.py | d:\a\triton\triton\llvm-project\build\bin\filecheck.exe D:\a\triton\triton\llvm-project\mlir\test\python\ir\auto_location.py
# executed command: C:/hostedtoolcache/windows/Python/3.11.9/x64/python3.exe 'D:\a\triton\triton\llvm-project\mlir\test\python\ir\auto_location.py'
# executed command: 'd:\a\triton\triton\llvm-project\build\bin\filecheck.exe' 'D:\a\triton\triton\llvm-project\mlir\test\python\ir\auto_location.py'
# .---command stderr------------
# | D:\a\triton\triton\llvm-project\mlir\test\python\ir\auto_location.py:37:11: error: CHECK: expected string not found in input
# |  # CHECK: loc(callsite("testInferLocations"("{{.*}}[[SEP:[/\\]]]test[[SEP]]python[[SEP]]ir[[SEP]]auto_location.py":31:13 to :43) at callsite("run"("{{.*}}[[SEP]]test[[SEP]]python[[SEP]]ir[[SEP]]auto_location.py":13:4 to :7) at "<module>"("{{.*}}[[SEP]]test[[SEP]]python[[SEP]]ir[[SEP]]auto_location.py":26:1 to :4))))
# |           ^
# | <stdin>:2:25: note: scanning from here
# | TEST: testInferLocations
# |                         ^
# | 
# | Input file: <stdin>
# | Check file: D:\a\triton\triton\llvm-project\mlir\test\python\ir\auto_location.py
# | 
# | -dump-input=help explains the following input dump.
# | 
# | Input was:
# | <<<<<<
# |           1:  
# |           2: TEST: testInferLocations 
# | check:37                             X error: no match found
# |           3: loc(callsite("testInferLocations"("D:\\a\\triton\\triton\\llvm-project\\mlir\\test\\python\\ir\\auto_location.py":31:13 to :43) at callsite("run"("D:\\a\\triton\\triton\\llvm-project\\mlir\\test\\python\\ir\\auto_location.py":13:4 to :7) at "<module>"("D:\\a\\triton\\triton\\llvm-project\\mlir\\test\\python\\ir\\auto_location.py":26:1 to :4)))) 
# | check:37     
```

Author: anmyachev

mlir/test/python/ir/auto_location.py

@@ -34,7 +34,7 @@ def testInferLocations():
         two = arith.constant(IndexType.get(), 2)
 
         # fmt: off
-        # CHECK: loc(callsite("testInferLocations"("{{.*}}[[SEP:[/\\]]]test[[SEP]]python[[SEP]]ir[[SEP]]auto_location.py":31:13 to :43) at callsite("run"("{{.*}}[[SEP]]test[[SEP]]python[[SEP]]ir[[SEP]]auto_location.py":13:4 to :7) at "<module>"("{{.*}}[[SEP]]test[[SEP]]python[[SEP]]ir[[SEP]]auto_location.py":26:1 to :4))))
+        # CHECK: loc(callsite("testInferLocations"("{{.*}}[[SEP:[/\\]+]]test[[SEP]]python[[SEP]]ir[[SEP]]auto_location.py":31:13 to :43) at callsite("run"("{{.*}}[[SEP]]test[[SEP]]python[[SEP]]ir[[SEP]]auto_location.py":13:4 to :7) at "<module>"("{{.*}}[[SEP]]test[[SEP]]python[[SEP]]ir[[SEP]]auto_location.py":26:1 to :4))))
         # fmt: on
         print(op.location)