Factor Cortex-M FVP e2e job into a reusable workflow and add nightly (#19070)

### Summary

Introduces .github/workflows/_test_cortex_m_e2e.yml as a local reusable
workflow that wraps pytorch/test-infra/linux_job_v2.yml with typed
models and timeout inputs. Both the existing per-commit trunk job and a
new nightly job now call it with only their matrix entries and timeouts.

The trunk matrix is unchanged ([mv2, mv3]). The new
test-cortex-m-e2e-nightly job covers four additional models on a daily
cadence: ds_cnn (MLPerf Tiny keyword spotting), mobilenet_v1_025 (MLPerf
Tiny Visual Wake Words / person-detection reference), resnet8 (MLPerf
Tiny image classification), and deep_autoencoder (MLPerf Tiny anomaly
detection).

This follows the same pattern as _test_cadence.yml.

This change was authored with Claude (claude-opus-4-7[1m]).

### Test plan
CI

Author: rascani

.github/workflows/_test_cortex_m_e2e.yml

@@ -0,0 +1,50 @@
+name: Test Cortex-M e2e
+
+permissions:
+  id-token: write
+  contents: read
+
+on:
+  workflow_call:
+    inputs:
+      models:
+        description: 'JSON array of model names to run on the Corstone-300 FVP, e.g. ["mv2", "mv3"]'
+        required: true
+        type: string
+      timeout:
+        description: 'Per-matrix-entry timeout in minutes'
+        required: false
+        type: number
+        default: 120
+
+jobs:
+  run:
+    uses: pytorch/test-infra/.github/workflows/linux_job_v2.yml@main
+    strategy:
+      matrix:
+        model: ${{ fromJSON(inputs.models) }}
+      fail-fast: false
+    with:
+      job-name: ${{ matrix.model }}
+      runner: linux.2xlarge.memory
+      docker-image: ci-image:executorch-ubuntu-22.04-arm-sdk
+      submodules: 'recursive'
+      ref: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}
+      timeout: ${{ inputs.timeout }}
+      script: |
+        # The generic Linux job chooses to use base env, not the one setup by the image
+        CONDA_ENV=$(conda env list --json | jq -r ".envs | .[-1]")
+        conda activate "${CONDA_ENV}"
+
+        source .ci/scripts/utils.sh
+        install_executorch "--use-pt-pinned-commit"
+
+        # Install arm dependencies
+        .ci/scripts/setup-arm-baremetal-tools.sh
+        source examples/arm/arm-scratch/setup_path.sh
+
+        # Build cortex-m test runner with bundled IO support
+        backends/cortex_m/test/build_test_runner.sh
+
+        # Export model and run on FVP
+        bash .ci/scripts/test_cortex_m_e2e.sh ${{ matrix.model }}

.github/workflows/nightly.yml

@@ -37,6 +37,16 @@ jobs:
     with:
       ref: ${{ github.sha }}
 
+  test-cortex-m-e2e-nightly:
+    name: test-cortex-m-e2e-nightly
+    permissions:
+      id-token: write
+      contents: read
+    uses: ./.github/workflows/_test_cortex_m_e2e.yml
+    with:
+      models: '["ds_cnn", "mobilenet_v1_025", "resnet8", "deep_autoencoder"]'
+      timeout: 180
+
   test-static-hf-llm-qnn-linux:
     name: test-static-hf-llm-qnn-linux
     uses: pytorch/test-infra/.github/workflows/linux_job_v2.yml@main

.github/workflows/trunk.yml

@@ -1091,34 +1091,9 @@ jobs:
 
   test-cortex-m-e2e:
     name: test-cortex-m-e2e
-    uses: pytorch/test-infra/.github/workflows/linux_job_v2.yml@main
-    strategy:
-      matrix:
-        model: [mv2, mv3]
-      fail-fast: false
     permissions:
       id-token: write
       contents: read
+    uses: ./.github/workflows/_test_cortex_m_e2e.yml
     with:
-      runner: linux.2xlarge.memory
-      docker-image: ci-image:executorch-ubuntu-22.04-arm-sdk
-      submodules: 'recursive'
-      ref: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}
-      timeout: 120
-      script: |
-        # The generic Linux job chooses to use base env, not the one setup by the image
-        CONDA_ENV=$(conda env list --json | jq -r ".envs | .[-1]")
-        conda activate "${CONDA_ENV}"
-
-        source .ci/scripts/utils.sh
-        install_executorch "--use-pt-pinned-commit"
-
-        # Install arm dependencies
-        .ci/scripts/setup-arm-baremetal-tools.sh
-        source examples/arm/arm-scratch/setup_path.sh
-
-        # Build cortex-m test runner with bundled IO support
-        backends/cortex_m/test/build_test_runner.sh
-
-        # Export model and run on FVP
-        bash .ci/scripts/test_cortex_m_e2e.sh ${{ matrix.model }}
+      models: '["mv2", "mv3"]'