fix has_***_filter functions to use c interface

Author: jswhit2

.github/workflows/miniconda.yml

@@ -45,8 +45,8 @@ jobs:
 
     - name: Tests
       run: |
-        export NO_PLUGINS=YES
-        #export HDF5_PLUGIN_PATH="${CONDA_PREFIX}/hdf5/lib/plugin/"
+        #export NO_PLUGINS=YES
+        export HDF5_PLUGIN_PATH="${CONDA_PREFIX}/hdf5/lib/plugin/"
         pytest -s -rxs -v test
 
   run-mpi:

src/netCDF4/_netCDF4.pyx

@@ -3558,10 +3558,11 @@ to be installed and in `$PATH`.
         """**`has_blosc_filter(self)`**
         returns True if blosc compression filter is available
         """
-        if __has_blosc_support__:
-            return True
-        else:
-            return False
+
+        #if __has_blosc_support__:
+        #    return True
+        #else:
+        #    return False
 
         cdef int ierr
         with nogil:
@@ -3573,10 +3574,10 @@ to be installed and in `$PATH`.
         returns True if zstd compression filter is available
         """
 
-        if __has_zstandard_support__:
-            return True
-        else:
-            return False
+        #if __has_zstandard_support__:
+        #    return True
+        #else:
+        #    return False
 
         cdef int ierr
         with nogil:
@@ -3588,10 +3589,10 @@ to be installed and in `$PATH`.
         returns True if bzip2 compression filter is available
         """
 
-        if __has_bzip2_support__:
-            return True
-        else:
-            return False
+        #if __has_bzip2_support__:
+        #    return True
+        #else:
+        #    return False
 
         cdef int ierr
         with nogil:
@@ -3603,11 +3604,13 @@ to be installed and in `$PATH`.
         returns True if szip compression filter is available
         """
 
-        if not __has_ncfilter__:
-            return __has_szip_support__
+        #if not __has_ncfilter__:
+        #    return __has_szip_support__
 
-        if not __has_szip_support__:
-            return False
+        #if  __has_szip_support__:
+        #    return True
+        #else:
+        #    return False
 
         cdef int ierr
         with nogil: