Ignore F821 in numpy_usm_shared.py

Author: Diptorup Deb

.flake8

@@ -8,6 +8,9 @@ show-source = True
 exclude =
     versioneer.py
     dpctl/_version.py
+    build
+    conda.recipe
+    .git
 
 per-file-ignores =
     dpctl/__init__.py: F403, F401
@@ -24,6 +27,7 @@ per-file-ignores =
     dpctl/_sycl_queue_manager.pyx: E999, E225
     dpctl/memory/_memory.pyx: E999, E225, E226, E227
     dpctl/program/_program.pyx: E999, E225, E226, E227
+    dpctl/tensor/numpy_usm_shared.py: F821
     examples/cython/sycl_buffer/_buffer_example.pyx: E999, E225, E402
     examples/cython/sycl_direct_linkage/_buffer_example.pyx: E999, E225, E402
     examples/cython/usm_memory/blackscholes.pyx: E999, E225, E226, E402