Update CXXFLAGS in SYCL CIs #959

Job	Run time
🔄 Update Stub Files / Stubs	3m 58s
🐧 Ubuntu / [email protected] Debug	8m 39s
🐧 Ubuntu / [email protected] w/o MPI	2m 12s
🐧 Ubuntu / [email protected]	5m 19s
🐧 Ubuntu / [email protected] w/ libc++ w/ MPI	2m 27s
🐧 Ubuntu / [email protected] [email protected]	2m 30s
🪟 Windows / Clang w/o MPI Shared Debug	26m 13s
🪟 Windows / MSVC w/o MPI Static Release	1h 21m 0s
🐧 HIP / ROCm HIP 6.1	8m 47s
🔎 CodeQL / Analyze (python)	3m 39s
🐧 Intel / ICC	10m 34s
🐧 Intel / ICPX	23m 29s
🔎 CodeQL / Analyze (cpp)	18m 10s
🐧 Intel / oneAPI SYCL 3D	29m 24s
🍏 macOS / [email protected] w/o MPI	4m 43s
	3h 51m 4s

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