[Nova] Use pkg-helpers to modularize GHA Linux Conda Builds (#2650)

Summary: Pull Request resolved: https://github.com/pytorch/audio/pull/2650

Reviewed By: mehtanirav

Differential Revision: D39040559

Pulled By: osalpekar

fbshipit-source-id: df39e23d7c246728793aab969b8dc1070af88d75

.github/workflows/build_linux_conda.yml

@@ -5,7 +5,9 @@ on:
 
 jobs:
   run-reusable-build-workflow:
-    uses: pytorch/test-infra/.github/workflows/build_conda_linux_reusable.yml@fix_pre_post
+    uses: pytorch/test-infra/.github/workflows/build_conda_linux_reusable.yml@main
     with:
       domain: "torchaudio"
-      image: "pytorch/conda-builder:cpu"
+      docker_image: "pytorch/conda-builder:cpu"
+      python_version: "3.8"
+      gpu_arch_version: "cpu"