ext/libsamplerate: remove unneeded ign_dirs

src_dirs and include_dirs fully describes what to compile and what not.
diff --git a/ext/libsamplerate/pkg.yml b/ext/libsamplerate/pkg.yml
index a8164ac..4bb8089 100644
--- a/ext/libsamplerate/pkg.yml
+++ b/ext/libsamplerate/pkg.yml
@@ -29,16 +29,6 @@
 pkg.cflags: -DHAVE_STDBOOL_H -fsingle-precision-constant -DHAVE_CONFIG_H -DNDEBUG
 pkg.lflags: -lm
 
-pkg.ign_dirs:
-    - "@libsamplerate/Octave"
-    - "@libsamplerate/Win32"
-    - "@libsamplerate/cmake"
-    - "@libsamplerate/docs"
-    - "@libsamplerate/examples"
-    - "@libsamplerate/include"
-    - "@libsamplerate/m4"
-    - "@libsamplerate/tests"
-
 pkg.src_dirs:
     - "@libsamplerate/src"