fix(workflow): escape backslashes in OneAPI setvars.bat path for windows-sycl

Author: Gioee

.github/workflows/main.yml

@@ -346,10 +346,10 @@ jobs:
         run: |
           call "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\Build\vcvarsall.bat" x64
           if "${{ matrix.name }}" == "windows-sycl" (
-            if exist "%ONEAPI_ROOT%\setvars.bat" (
-              call "%ONEAPI_ROOT%\setvars.bat"
+            if exist "%ONEAPI_ROOT%\\setvars.bat" (
+              call "%ONEAPI_ROOT%\\setvars.bat"
             ) else (
-              echo OneAPI setvars.bat not found at %ONEAPI_ROOT%\setvars.bat
+              echo OneAPI setvars.bat not found at "%ONEAPI_ROOT%\\setvars.bat"
               dir "%ONEAPI_ROOT%"
             )
             where icx