refactor: consolidate is_in_ci (jit_kernel, sgl-kernel benchmarks, tests) (#21009)

sgl-kernel/benchmark/bench_fp8_gemm.py

@@ -9,6 +9,7 @@ import triton
 from sgl_kernel import fp8_scaled_mm as sgl_scaled_mm
 
 from sglang.jit_kernel.per_tensor_quant_fp8 import per_tensor_quant_fp8
+from sglang.utils import is_in_ci
 
 # Optional vLLM import
 try:
@@ -21,11 +22,7 @@ except ImportError:
     vllm_scaled_fp8_quant = None
     VLLM_AVAILABLE = False
 
-# CI environment detection
-IS_CI = (
-    os.getenv("CI", "false").lower() == "true"
-    or os.getenv("GITHUB_ACTIONS", "false").lower() == "true"
-)
+IS_CI = is_in_ci()
 
 # Weight Shapes are in the format
 # ([K, N], TP_SPLIT_DIM)