Replace deprecated pkg_resources with importlib.resources.

--- a/barectf/config_parse_common.py
+++ b/barectf/config_parse_common.py
@@ -21,7 +21,7 @@
 # TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 # SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
-import pkg_resources
+import importlib.resources
 import collections
 import jsonschema  # type: ignore
 import os.path
@@ -126,7 +126,7 @@
 # validate as well as a schema short ID.
 class _SchemaValidator:
     def __init__(self, subdirs: Iterable[str]):
-        schemas_dir = pkg_resources.resource_filename(__name__, 'schemas')
+        schemas_dir = importlib.resources.files(__name__).joinpath('schemas')
         self._store: Dict[str, str] = {}
 
         for subdir in subdirs:
@@ -350,7 +350,7 @@
         self._include_dirs = copy.copy(include_dirs)
 
         if with_pkg_include_dir:
-            self._include_dirs.append(pkg_resources.resource_filename(__name__, f'include/{major_version}'))
+            self._include_dirs.append(importlib.resources.files(__name__).joinpath(f'include/{major_version}'))
 
         self._ignore_include_not_found = ignore_include_not_found
         self._include_stack: List[str] = []