Add integration test for Linux with Nvidia GPU. #3884 (#3895)

* Add linux integration test.

* Fix directory path.

* Add paths ignore.

* Fix conda env directory path.

.github/conda-environments/linux-environment.yml

+name: comfyui
+channels:
+  - pytorch
+  - nvidia
+  - defaults
+dependencies:
+  - python>=3.9
+  - pip
+  - pytorch
+  - torchvision
+  - torchaudio
+  - pytorch-cuda=12.1
+  - pip:
+    # comfyui requirements
+    - einops
+    - transformers>=4.25.1
+    - safetensors>=0.4.2
+    - aiohttp
+    - pyyaml
+    - Pillow
+    - scipy
+    - tqdm
+    - psutil
+    # comfy-action requirements
+    - requests
+    - google-cloud-storage
+    - comfy-cli
+    - charset-normalizer
\ No newline at end of file

.github/workflows/linux-integration-test.yml

+name: (Linux) ComfyUI Integration Tests
+on:
+  push:
+    branches:
+      - master
+    paths-ignore:
+      - 'app/**'
+      - 'input/**'
+      - 'output/**'
+      - 'model/**'
+      - 'notebook/**'
+      - 'script_example/**'
+      - 'tests/**'
+      - 'tests-ui/**'
+      - '.github/**'
+      - '.ci/**'
+      - 'web/**'
+  workflow_dispatch:
+  pull_request:
+    branches:
+      - master
+    paths-ignore:
+      - 'app/**'
+      - 'input/**'
+      - 'output/**'
+      - 'model/**'
+      - 'notebook/**'
+      - 'script_example/**'
+      - 'tests/**'
+      - 'tests-ui/**'
+      - '.github/**'
+      - '.ci/**'
+      - 'web/**'
+
+jobs:
+  test-workflows:
+    runs-on: [self-hosted, Linux, t4] 
+    steps:
+    - name: Test ComfyUI Workflows
+      uses: comfy-org/comfy-action@main
+      with:
+        os: linux
+        cuda_version: 12.1
+        models-json: '{"v1-5-pruned-emaonly.ckpt": {"url": "https://huggingface.co/runwayml/stable-diffusion-v1-5/resolve/main/v1-5-pruned-emaonly.ckpt", "directory": "checkpoints"}}'
+        workflow_filenames: "default.json"
+        gcs_bucket_name: 'comfy-ci-results'
+        google_credentials: ${{ secrets.GCS_SERVICE_ACCOUNT_JSON }}
+        output_prefix: 'ComfyUI'
+        conda_env_file: '.github/conda-environments/linux-environment.yml'
+        timeout: 50