make vllm-ascend work well in developer mode (#4179)

### What this PR does / why we need it?
we often install vllm-ascend in developer mode, which has no _build_info
module. it will raise error in `utils.is_310p` and
`utils.sleep_model_enabled`, then we need to modify these two function.

### Does this PR introduce _any_ user-facing change?
not involved

### How was this patch tested?
not involved

- vLLM version: v0.11.0
- vLLM main:
2918c1b49c

Signed-off-by: Ronald1995 <ronaldautomobile@163.com>

setup.py

@@ -69,19 +69,7 @@ envs = load_module_from_path("envs",
                              os.path.join(ROOT_DIR, "vllm_ascend", "envs.py"))
 
 
-class CMakeExtension(Extension):
-
-    def __init__(self,
-                 name: str,
-                 cmake_lists_dir: str = ".",
-                 **kwargs) -> None:
-        super().__init__(name, sources=[], py_limited_api=False, **kwargs)
-        self.cmake_lists_dir = os.path.abspath(cmake_lists_dir)
-
-
-class custom_build_info(build_py):
-
-    def run(self):
+def gen_build_info():
     soc_version = envs.SOC_VERSION
     if not soc_version:
         raise ValueError(
@@ -96,10 +84,31 @@ class custom_build_info(build_py):
     with open(package_dir, "w+") as f:
         f.write('# Auto-generated file\n')
         f.write(f"__soc_version__ = '{soc_version}'\n")
-            f.write(
-                f"__sleep_mode_enabled__ = {envs.COMPILE_CUSTOM_KERNELS}\n")
-        logging.info(
-            f"Generated _build_info.py with SOC version: {soc_version}")
+        f.write(f"__sleep_mode_enabled__ = {envs.COMPILE_CUSTOM_KERNELS}\n")
+    logging.info(f"Generated _build_info.py with SOC version: {soc_version}")
+
+
+class CMakeExtension(Extension):
+
+    def __init__(self,
+                 name: str,
+                 cmake_lists_dir: str = ".",
+                 **kwargs) -> None:
+        super().__init__(name, sources=[], py_limited_api=False, **kwargs)
+        self.cmake_lists_dir = os.path.abspath(cmake_lists_dir)
+
+
+class custom_develop(develop):
+
+    def run(self):
+        gen_build_info()
+        super().run()
+
+
+class custom_build_info(build_py):
+
+    def run(self):
+        gen_build_info()
         super().run()
 
 
@@ -352,6 +361,7 @@ def get_requirements() -> List[str]:
 
 
 cmdclass = {
+    "develop": custom_develop,
     "build_py": custom_build_info,
     "build_ext": cmake_build_ext,
     "install": custom_install