Arm backend: Enable mypy for tests

Add test directory in arm backend to lintrunner. Except the ops
directory which has to be fixed later.

About "disallow_untyped_decorators = False":
The only way to make mypy happy seems to be a wrapper around the
decorator for each file it is used. I have read numerous of threads
about it and there seems to be no good solution. Hence the added
ignore for backends/arm.

Signed-off-by: [email protected]
Change-Id: I0430041cb3308b51798d74da61cc4d310966772a

Author: perheld

.lintrunner.toml

@@ -367,7 +367,7 @@ exclude_patterns = [
     '**/third-party/**',
     'scripts/check_binary_dependencies.py',
     'profiler/test/test_profiler_e2e.py',
-    'backends/arm/test/**',
+    'backends/arm/test/ops/*.py',
 ]
 command = [
     'python',

.mypy.ini

@@ -29,6 +29,9 @@ mypy_path = executorch,src
 [mypy-executorch.backends.*]
 follow_untyped_imports = True
 
+[mypy-backends.arm.*]
+disallow_untyped_decorators = False
+
 [mypy-executorch.codegen.*]
 follow_untyped_imports = True