ENH: drop empty strings when listing RPATH entries for ELF binaries

This entries are not meaningful. This has the additional benefit of
not returning an empty string RPATH entry for binaries with RPATH unset.

Author: dnicolodi

mesonpy/_rpath.py

@@ -74,7 +74,7 @@ def fix_rpath(filepath: Path, libs_relative_path: str) -> None:
 
     def _get_rpath(filepath: Path) -> List[str]:
         r = subprocess.run(['patchelf', '--print-rpath', os.fspath(filepath)], capture_output=True, text=True)
-        return r.stdout.strip().split(':')
+        return [x for x in r.stdout.strip().split(':') if x]
 
     def _set_rpath(filepath: Path, rpath: Iterable[str]) -> None:
         subprocess.run(['patchelf','--set-rpath', ':'.join(rpath), os.fspath(filepath)], check=True)