Cortex-M: keep NHWC channel broadcasts quantized - #21968

{"FAILED":[{"workflowId":32907665367,"workflowUniqueId":63454257,"id":97995194046,"runnerName":"i-05c597e63a7846b27","authorEmail":"rja@meta.com","name":"pull / test-arm-backend-no-driver (test_pytest_ops_tosa) / linux-job","jobName":"test-arm-backend-no-driver (test_pytest_ops_tosa) / linux-job","conclusion":"cancelled","completed_at":"2026-08-26T00:32:13.000000000Z","html_url":"https://github.com/pytorch/executorch/actions/runs/32907665367/job/97995194046","logUrl":"https://ossci-raw-job-status.s3.amazonaws.com/log/pytorch/executorch/97995194046","head_branch":"gh/rascani/14/head","pr_number":21968,"head_sha":"82150a8c819caa746b6234d98783bc68b6578fee","head_sha_timestamp":"2026-08-25T22:45:18.000000000Z","failure_captures":["##[error]The operation was canceled."],"failure_lines":["##[error]The operation was canceled."],"failure_context":[],"time":"2026-08-25T22:45:45.000000000Z"},{"workflowId":32907665492,"workflowUniqueId":188272584,"id":97995153589,"runnerName":"i-079470064e1bf01c4","authorEmail":"rja@meta.com","name":"Test ARM Backend / test-arm-vgf / test-backend-linux (arm_vgf_fp, operators) / linux-job","jobName":"test-arm-vgf / test-backend-linux (arm_vgf_fp, operators) / linux-job","conclusion":"cancelled","completed_at":"2026-08-26T00:52:21.000000000Z","html_url":"https://github.com/pytorch/executorch/actions/runs/32907665492/job/97995153589","logUrl":"https://ossci-raw-job-status.s3.amazonaws.com/log/pytorch/executorch/97995153589","head_branch":"gh/rascani/14/head","pr_number":21968,"head_sha":"82150a8c819caa746b6234d98783bc68b6578fee","head_sha_timestamp":"2026-08-25T22:45:18.000000000Z","failure_captures":["##[error]The operation was canceled."],"failure_lines":["##[error]The operation was canceled."],"failure_context":[],"time":"2026-08-25T22:45:35.000000000Z"},{"workflowId":32907665492,"workflowUniqueId":188272584,"id":97995153714,"runnerName":"i-057126510cac8a227","authorEmail":"rja@meta.com","name":"Test ARM Backend / test-arm / test-backend-linux (arm_tosa_fp, operators) / linux-job","jobName":"test-arm / test-backend-linux (arm_tosa_fp, operators) / linux-job","conclusion":"cancelled","completed_at":"2026-08-26T00:52:22.000000000Z","html_url":"https://github.com/pytorch/executorch/actions/runs/32907665492/job/97995153714","logUrl":"https://ossci-raw-job-status.s3.amazonaws.com/log/pytorch/executorch/97995153714","head_branch":"gh/rascani/14/head","pr_number":21968,"head_sha":"82150a8c819caa746b6234d98783bc68b6578fee","head_sha_timestamp":"2026-08-25T22:45:18.000000000Z","failure_captures":["##[error]The operation was canceled."],"failure_lines":["##[error]The operation was canceled."],"failure_context":[],"time":"2026-08-25T22:45:35.000000000Z"}],"FLAKY":[{"workflowId":32907665367,"workflowUniqueId":63454257,"id":97995194147,"runnerName":"i-09481806b30a7e0f1","authorEmail":"rja@meta.com","name":"pull / test-arm-backend-no-driver (test_pytest_models_tosa) / linux-job","jobName":"test-arm-backend-no-driver (test_pytest_models_tosa) / linux-job","conclusion":"failure","completed_at":"2026-08-26T00:22:39.000000000Z","html_url":"https://github.com/pytorch/executorch/actions/runs/32907665367/job/97995194147","logUrl":"https://ossci-raw-job-status.s3.amazonaws.com/log/pytorch/executorch/97995194147","head_branch":"gh/rascani/14/head","pr_number":21968,"head_sha":"82150a8c819caa746b6234d98783bc68b6578fee","head_sha_timestamp":"2026-08-25T22:45:18.000000000Z","failure_captures":[],"failure_lines":[],"failure_context":[],"time":"2026-08-25T22:45:45.000000000Z"}],"BROKEN_TRUNK":[],"UNSTABLE":[],"UNKNOWN":[],"AWAITING_APPROVAL":[]}