Add cache option to setup action

actions/setup/action.yml

@@ -9,6 +9,10 @@ inputs:
     description: Python version (passed to actions/setup-python)
     required: false
     default: "3"
+  cache:
+    description: Enable/disable caching of pip/conda downloads
+    required: false
+    default: "true"
 runs:
   using: composite
   steps:
@@ -19,9 +23,10 @@ runs:
       with:
         create-args: python=${{ inputs.python-version }}
         environment-name: ci
-        cache-downloads: true
+        cache-downloads: ${{ inputs.cache }}
         generate-run-shell: false
     - uses: actions/cache@v4
+      if: ${{ inputs.cache == 'true' }}
       with:
         path: ~/.cache/pip
         key: ${{ runner.os }}-pip