just use main directly

Signed-off-by: Peter St. John <pstjohn@nvidia.com>

Author: pstjohn

.github/workflows/bionemo-recipes.yml

@@ -27,16 +27,11 @@ jobs:
         with:
           fetch-depth: 0
 
-      - name: Get main branch latest commit
-        id: main-commit
-        run: |
-          echo "main_commit=$(git rev-parse main)" >> $GITHUB_OUTPUT
-
       - name: Get changed files
         id: changed-files
         uses: step-security/changed-files@v46
         with:
-          base_sha: ${{ steps.main-commit.outputs.main_commit }}
+          base_sha: main
 
       - name: List all changed files
         env: