nvcc: avoid adding -Wpedantic to compile lines

* `-Wpedantic` creates useless churn due to its use of gcc-line directives:
  ../foo.cu:1:3: warning: style of line directive is a GCC extension
      1 | namespace Foo {
        |   ^~
  https://stackoverflow.com/a/31001220

mesonbuild/compilers/cuda.py

@@ -192,7 +192,13 @@ def __init__(self, ccache: T.List[str], exelist: T.List[str], version: str, for_
         self.exe_wrapper = exe_wrapper
         self.host_compiler = host_compiler
         self.base_options = host_compiler.base_options
-        self.warn_args = {level: self._to_host_flags(flags) for level, flags in host_compiler.warn_args.items()}
+        # -Wpedantic generates useless churn due to nvcc's dual compilaton model producing
+        # a temporary host C++ file that includes gcc-style line directives:
+        # https://stackoverflow.com/a/31001220
+        self.warn_args = {
+            level: self._to_host_flags(f for f in flags if f != '-Wpedantic')
+            for level, flags in host_compiler.warn_args.items()
+        }
 
     @classmethod
     def _shield_nvcc_list_arg(cls, arg: str, listmode: bool = True) -> str: