Don't recommend deprecated pkg_resources package

Use std library importlib.metadata.version as the current
recommended alternative

opentelemetry-api/src/opentelemetry/_logs/_internal/__init__.py

@@ -143,7 +143,7 @@ def get_logger(
 
             version: Optional. The version string of the
                 instrumenting library.  Usually this should be the same as
-                ``pkg_resources.get_distribution(instrumenting_library_name).version``.
+                ``importlib.metadata.version(instrumenting_library_name)``.
 
             schema_url: Optional. Specifies the Schema URL of the emitted telemetry.
         """