Add NVHPC (__PGI) to the list of compilers compatible with system compiler.

See comment by @robertmaynard: #5439 (comment)

Author: rwgk

include/pybind11/conduit/pybind11_platform_abi_id.h

@@ -29,9 +29,7 @@
 #        define PYBIND11_COMPILER_TYPE "_gcc_cygwin"
 #    elif defined(_MSC_VER)
 #        define PYBIND11_COMPILER_TYPE "_msvc"
-#    elif defined(__PGI)
-#        define PYBIND11_COMPILER_TYPE "_pgi"
-#    elif defined(__INTEL_COMPILER) || defined(__clang__) || defined(__GNUC__)
+#    elif defined(__INTEL_COMPILER) || defined(__PGI) || defined(__clang__) || defined(__GNUC__)
 #        define PYBIND11_COMPILER_TYPE "_system" // Assumed compatible with system compiler.
 #    else
 #        error "Unknown PYBIND11_COMPILER_TYPE: PLEASE REVISE THIS CODE."