initialize more shells

Author: tayden

.github/workflows/_conda-build.yml

@@ -54,7 +54,10 @@ jobs:
             -c pytorch -c nvidia -c conda-forge
           cache-downloads: true
           cache-downloads-key: ${{ runner.os }}-${{ runner.arch }}-${{ env.CACHE_NUMBER }}
-          init-shell: bash
+          init-shell: >-
+            bash
+            powershell
+            cmd.exe
 
       - name: Verify rattler-build installation
         run: rattler-build --version