Force mypy colors in CI

Both the [GitHub Actions log viewer](https://github.uint.cloudmunity/t/ansi-color-output-in-webview/17621) and the HUD PR page log viewer support ANSI color codes so turn those on via this [secret env variable](python/mypy#7771)

ghstack-source-id: 77b47d6e1e449f69a44e24a5095c4980f92a383f
Pull Request resolved: pytorch/pytorch#61391

.github/workflows/lint.yml

@@ -404,6 +404,9 @@ jobs:
           time python -mtools.codegen.gen -s aten/src/ATen -d build/aten/src/ATen
           time python -mtools.pyi.gen_pyi --native-functions-path aten/src/ATen/native/native_functions.yaml --deprecated-functions-path "tools/autograd/deprecated.yaml"
       - name: Run mypy
+        env:
+          MYPY_FORCE_COLOR: 1
+          TERM: xterm-color
         run: |
           set -eux
           STATUS=